McQuay AGZ 034BS, AGZ 034BM, AGZ 010BM Operation Manual

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Installation, Operation and Maintenance Manual

IOMM AGZB1

Air-Cooled Scroll Compressor Water Chillers

AGZ 010BS – AGZ 034BS, Packaged Chiller AGZ 010BM – AGZ 034BM, Remote Evaporator

10 to 34 Tons, 35 to 120 kW

R-22, R-407C

60 Hertz

Software Version AGZSU0102D

Group: Chiller

Part Number: 331975001

Effective: October 2007

Supersedes: New

Table of Contents

Introduction ....................................... 3

General Description...................................3

Inspection ..................................................3

Installation .................................................3

Handling ....................................................3

Location.....................................................4

Service Access...........................................4

Vibration Isolators.....................................6

Chilled Water System ................................6

Water Connections ....................................9

Refrigerant Charge ....................................9

Unit Component Location .........................9

Glycol Solutions ......................................10

Evaporator Water Flow and Pressure Drop10

R-407C Units.................................... 12

Control Layout and Operation ...... 14

Control Center .........................................14

Start-up and Shutdown................... 14

Pre Start-up..............................................14

Start-up ....................................................14

Sequence of Operation ............................15

Physical Data.................................... 16

AGZ-BS, R-22/R-407C ...........................16

AGZ-BM, R-22/R-407C..........................18

Electrical Data ................................. 20

Field Wiring.............................................20

R-22 .........................................................20

R-407C ....................................................23

Dimensions & Weights .................... 28

Remote Evaporators ................................30

ACZ/AGZ Dimensions and Weights .......31

System Maintenance........................ 32

General ....................................................32

Lubrication.............................................. 32

Electrical Terminals................................ 32

Condensers.............................................. 32

Refrigerant Sight glass............................ 32

Standard MicroTech II Controller.33

Table of Contents.................................... 33

Overview................................................. 34

General Description ................................ 34

Setpoint Security..................................... 38

Equipment Protection Alarms................. 38

Control Functions and Definitions ......... 39

Unit Enable ............................................. 41

Unit Mode ............................................... 41

Power Up Start Delay ............................. 42

Ice Mode Start Delay .............................. 42

Unit State ................................................ 42

Evaporator Water Pump State Control.... 43

Condenser Fans....................................... 44

Low OAT Start........................................ 44

Circuit Capacity Overrides ..................... 44

Maximum LWT Rate .............................. 45

Low Ambient Lockout ............................ 45

Compressor Control................................ 45

Using the Controller ............................... 48

Menu Screens.......................................... 49

BAS Interface...................................61

Service...............................................62

Thermostatic Expansion Valve ............... 62

Filter-Driers ............................................ 62

Liquid Line Solenoid .............................. 62

Optional Controls.................................... 63

Troubleshooting Chart ............................ 66

©2007 McQuay International. Illustrations and data cover the McQuay International product at the time of publication and we reserve the right to make changes in design and construction at anytime without notice. ™® The following are trademarks or registered trademarks of their respective companies: BACnet from ASHRAE; LONM logo are managed, granted and used by LONM from Copeland Corporation; ElectroFin from AST ElectroFin Inc.; Modbus from Schneider Electric; FanTrol, MicroTech II, Open Choices, and SpeedTrol from McQuay International.

2 AGZ 010B through 034B IOMM AGZB1

ARK

International under a license granted by Echelon Corporation; Compliant Scroll

, LonTalk, LONW

ORKS

, and the LONM

ARK

Introduction

General Description

McQuay air-cooled water chillers are complete, self-contained automatic refrigerating units. Every unit is completely assembled, factory wired, charged, and tested. Each unit consists of air-cooled condensers, Copeland Compliant Scroll hermetic compressor, brazed plate-toplate evaporator, and complete refrigerant piping. Liquid line components include sightglass/moisture indicator, solenoid valve, and thermal expansion valve. Other features include a compressor heater, and evaporator heater for chilled water freeze protection.

The electrical control center includes all equipment protection and operating controls necessary for automatic operation. Condenser fan motors are three-phase (except single-phase on No. 1 fan with SpeedTrol option) and started by their own contactors and have inherent overload protection. Each compressor has solid-state motor protection for inherent thermal overload protection except Model AGZ 010 that has internal line breakage.

Software Version

This manual is based on software version AGZSU0102D. The software version can be displayed by pressing the Enter and Menu keys simultaneously. Exit by pressing Menu.

Inspection

Check all items carefully against the bill of lading. Inspect all units for damage upon arrival. Report shipping damage and file a claim with the carrier. Check the unit nameplate before unloading to be sure it agrees with the power supply available. Units are shipped FOB factory and McQuay is not responsible for physical damage after unit leaves the factory.

Note: Unit shipping and operating weights are listed on pages 16 and 17.

Installation

Note: Installation must be performed by trained, experienced personnel who are

familiar with local codes and regulations, especially concerning refrigerant release to the atmosphere.

WARNING

Sharp edges and coil surfaces can cause personal injury. Avoid contact with them.

Handling

Be careful to avoid rough handling of the unit. Do not push or pull the unit from anything other than the base. Block the pushing vehicle away from the unit to prevent damage to the sheet-metal cabinet and end frame (see Figure 1).

To lift the unit, lifting slots are provided in the base of the unit. Arrange spreader bars and cables to prevent damage to the condenser coils or cabinet (see Figure 2).

AZARD IDENTIFICATION INFORMATION

WARNING

Warnings indicate potentially hazardous situations, which can result in property damage, severe

personal injury, or death if not avoided.

CAUTION

Cautions indicate potentially hazardous situations, which can result in personal injury or

IOMM AGZB1 AGZ 010B through 034B 3

equipment damage if not avoided.

BLOCKING REQUIRED

ACROSS FULL WIDTH

SPREADER BAR (2)

PIPE SLUNG THRU

OPENINGS IN LEGS (2)

Figure 1, Suggested Pushing Arrangement

Figure 2, Suggested Lifting Arrangement

NOTE:: The fork lift slots can be used for lifting by inserting sufficiently strong pipe through them as shown in Figure 2. Use the outboard slots on three-fan units and the only two on two-fan units.

Location

Unit Placement

AGZ units are for outdoor applications and can be mounted on a roof or at ground level. Set units on a solid and level foundation. For roof-mounted applications, install the unit on a steel channel or I-beam frame to support the unit above the roof. For ground level applications, install the unit on a substantial base that will not settle. A one-piece concrete slab with footings extended below the frost line is recommended. Be sure the foundation is level (within 1/2” [13 mm] over its length and width). The foundation must support the operating weights listed in the Physical Data Tables on pages 16 and 17. It is recommended that the unit be raised a few inches with a suitable support, located at least under the mounting locations, to allow water to drain from under the unit and to facilitate cleaning under it.

Since its operation is affected by wind, the unit should be located so that its length is parallel with the prevailing wind. If this is not practical, use field fabricated wind deflectors.

Service Access

Each end of the unit must be accessible after installation for periodic service. Compressors, filter-driers, and liquid line solenoid valve are accessible from the end of the unit. Highpressure, low-pressure, and motor protector controls are on the compressor. Most operating, equipment protection, and starting controls are located in the unit control box.

4 AGZ 010B through 034B IOMM AGZB1

The fan deck with the condenser fans and motors can be removed from the top of the unit.

4 Ft.

Clearance for Air Inlet

The recommended minimum side clearance between two units

The unit must not be installed in a pit or enclosure that is

deeper or taller than the height of the unit unless extra space

unit is 6 feet (1828mm) when installed in a pit. The pit cannot

Clearances

The flow of air to and from the condenser coil must not be limited. Restricting airflow or allowing air recirculation will result in a decrease in unit performance and efficiency. There must be no obstruction above the unit that would deflect discharge air downward where it could be recirculated back to the inlet of the condenser coil. The condenser fans are propeller type and will not operate with ductwork on the fan outlet.

Install the unit with enough side clearance for air entrance to the coil and for servicing. Provide service access to the evaporator, compressors, electrical control panel and piping components as shown in Figure 3. Do not block access to the unit with piping or conduit.

Do not allow debris to accumulate near the unit. Air movement may draw debris into the condenser coil causing air starvation. Give special consideration to low ambient operation where snow can accumulate. Keep condenser coils and fan discharge free of snow or other obstructions to permit adequate airflow.

Figure 3, Clearance requirements

4 Ft. (1220mm)

(1220mm)

Clearance for

Service Access

4 Ft. (1220mm)

is 8 feet (2440mm).

4 Ft.

(1220mm)

Clearance for

Service Access

Sound Isolation

The low sound levels of the AGZ chiller are suitable for most applications. When additional sound reduction is necessary, locate the unit away from sound sensitive areas. Avoid locations beneath windows or between structures where normal operating sounds may be objectionable. Reduce structurally transmitted sound by isolating water lines, electrical conduit and the unit itself. Use wall sleeves and rubber isolated piping hangers to reduce transmission of water or pump noise into occupied spaces. Use flexible electrical conduit to isolate sound through electrical conduit. Spring isolators are effective in reducing the low amplitude sound generated by the Discus semi-hermetic compressors and for unit isolation in sound-sensitive areas.

is provided. The minimum clearance on each side of the

be deeper than the unit.

The minimum clearance to a side wall or building taller than the unit height is 6 feet (1828mm) provided no solid wall above 6 feet (1828mm) tall is closer than 12 feet (3658mm) to the opposite side of the unit.

IOMM AGZB1 AGZ 010B through 034B 5

Vibration Isolators

Vibration isolators are recommended for all roof-mounted installations or wherever vibration transmission is a consideration.

The unit should be initially placed on shims or blocks at the listed free height. When all piping, wiring, flushing, charging, etc. is completed, the springs are adjusted upward to loosen the blocks or shims that are then removed.

A rubber anti-skid pad is part of the isolator. Installation of spring isolators requires flexible piping connections and at least three feet of flexible conduit to avoid straining the piping and transmitting vibration and noise. These units cannot be bolted to isolators.

Table 1, Recommended Vibration Isolators

Neoprene-in-Shear

AGZ Model RF LF RB LB

010, 013, 017 RP-3 Red RP-3 Red RP-3 Red RP-3 Red 350014858 020, 025, 029, 034 RP-3 Green RP-3 Green RP-3 Red RP-3 Red 350014857

Spring

AGZ Mod el RF LF RB LB

010 CP 1-24 Brown CP 1-24 Brown CP 1-24 Brown CP 1-24 Brown 3500148 32 013, 017 CP 1-25 Red CP 1-25 Red CP 1-25 Red CP 1-25 Red 3500148 34 020, 025 CP1-26 Purple CP1-27 Orange CP 1-24 Brown CP 1-24 Brown 3500148 36 029 CP1-27 Orange CP1-2 7 Orange CP 1-25 Red CP 1-25 Red 3500148 38 034 CP1-27 Orange CP1 -2 8 Green CP 1-25 Red CP 1-25 Red 350014840

Note: See dimension drawing for location of isolators

Kit P/N

Corner Weights

Packaged Chiller

AGZ-

010A 013A 017A 020A 025A 029A 034A

RF LF RB LB

279 275 267 263 315 297 288 271 344 323 316 297 502 475 271 257 531 496 301 282 583 238 353 326 779 761 369 361

R BI

L BI

Control

Panel

R FI

L FI

Remote Evaporator

AGZ-

010A 013A 017A

020A 446 443 241 240

025A 029A 034A

LF RF LB RB

257 264 236 243 290 286 246 243 312 309 266 263

453 449 245 243 488 487 296 295 656 703 297 318

CP-1, Spring Isolator RP-3 Neoprene-in-Shear Isolator

6 AGZ 010B through 034B IOMM AGZB1

Chilled Water System

Water Piping

Local authorities can supply the installer with the proper building and safety codes required for proper installation.

Install piping with minimum bends and changes in elevation to minimize pressure drop. Consider the following when installing water piping:

1. Vibration eliminators to reduce vibration and noise transmission to the building.

2. Shutoff valves to isolate the unit from the piping system during unit servicing.

3. Manual or automatic air vent valves at the high points of the system. Install drains at

the lowest points in the system.

4. Maintaining adequate system water pressure (expansion tank or regulating valve).

5. Temperature and pressure indicators located at the unit to aid in unit servicing.

Pressure gauge taps must be installed in the chilled water inlet and outlet piping or as shown in Figure 4.

6. A strainer or other means of removing foreign matter from the water before it enters the

pump. Place the strainer far enough upstream to prevent cavitation at the pump inlet (consult pump manufacturer for recommendations). The use of a strainer can prolong pump life and keep system performance up.

7. A 40-mesh strainer is required in the water line just before the inlet of the evaporator.

This will help prevent foreign material from entering and decreasing the performance of the evaporator.

CAUTION

If a separate disconnect is used for the 110V supply to the evaporator heating cable, mark the disconnect clearly so the disconnect is not accidentally shut off during cold seasons. Failure to do so can cause a failure of the evaporator.

8. The brazed plate evaporator has a thermostat and heating cable to prevent freeze-up

down to -20°F (-29°C). The heating cable should be wired to a separate 110V supply circuit. As shipped from the factory, the heating cable is wired to the control circuit. Protect all water piping to the unit from freezing.

9. If the unit is used as a replacement chiller on a previously existing piping system, flush

the system thoroughly before unit installation. Perform regular water analysis and chemical water treatment on the evaporator immediately at equipment start-up.

10. When glycol is added to the water system for freeze protection, the refrigerant suction

pressure will be lower, cooling performance less, and water side pressure drop greater. If the percentage of glycol is high, or if propylene is used instead of ethylene glycol, the added pressure drop and loss of performance could be substantial. Reset the freezestat and low leaving water alarm temperatures. The freezestat is factory set to default at 38°F (3.3°C). Reset the freezestat setting to approximately 4 to 5 degrees F (2.3 to 2.8 degrees C) below the leaving chilled water setpoint temperature. See the section titled “Glycol Solutions” on page 10 for additional information concerning glycol.

11. Perform a preliminary leak check before insulating the piping and filling the system.

12. Include a vapor barrier on the piping insulation to prevent condensation and possible

damage to the building structure.

IOMM AGZB1 AGZ 010B through 034B 7

Figure 4, Typical Field Evaporator Water Piping

Air

Flow

Switch

Vibration

Eliminators

Drain

Isolation

Strainer

Vent

Inlet

Outlet

Valves

NOTES:

1. Chilled water piping within the unit enclosure must be insulated in the field.

2. Support piping independently of the unit and install per local codes.

System Volume

It is important to have adequate water volume in the system to provide an opportunity for the chiller to sense a load change, adjust to the change and stabilize. As the expected load change becomes more rapid, a greater water volume is needed. The system water volume is the total amount of water in the evaporator, air handling products and associated piping. If the water volume is too low, operational problems can occur, including rapid compressor cycling, rapid loading and unloading of compressors, erratic refrigerant flow in the chiller, improper motor cooling, shortened equipment life and other undesirable occurrences.

For normal comfort cooling applications, where the cooling load changes relatively slowly, we recommend a minimum system volume of three to four times the flow rate (GPM). For example, if the design chiller flow rate is 120 GPM, we recommend a minimum system volume of 360 to 480 gallons.

Since there are many other factors that can influence performance, systems may successfully operate below these suggestions. However, as the water volume decreases below these suggestions, the possibility of problems increases.

Variable Chilled Water flow

Variable chilled water flow systems are not recommended for this class of equipment due to limited unloading capability.

Flow Switch

Mount a water flow switch in the leaving water line to shut down the unit when water flow is interrupted.

A flow switch is available from McQuay (part number 017503300). It is a “paddle” type switch and adaptable to pipe sizes down to 1 1/4” (32mm) nominal. Certain minimum flow rates are required to close the switch and are listed in Table 2. Install the switch as shown in Figure 5. Connect the normally open contacts of the flow switch in the unit control center at terminals 4 and 5. There is also a set of normally closed contacts on the switch that can be used for an indicator light or an alarm to indicate when a “no-flow”

Figure 5, Flow Switch Installation

8 AGZ 010B through 034B IOMM AGZB1

condition exists. Freeze protect any flow switch that is installed outdoors. Follow installation instructions provided with the flow switch. Calibrate the flow switch to open at one-half of nominal flow rate.

NOTE: Differential pressure switches are not recommended for outdoor installation. They are subject to damage from freezing.

Table 2, Flow Switch Settings

(NOTE !)

Min.

Adjst.

Max.

Adjst.

Flow

Flow Lpm 0.8 1.1 2.2 2.8 4.3 11.4 22.9 35.9 38.6

Flow

Flow Lpm 2.8 4.1 6.1 7.3 11.4 27.7 53.4 81.8 90.8

NOTES:

1. A segmented 3-inch paddle (1, 2, and 3 inches) is furnished mounted, plus a 6-inch paddle loose.

2. Flow rates for a 2-inch paddle trimmed to fit the pipe.

3. Flow rates for a 3-inch paddle trimmed to fit the pipe.

4. Flow rates for a 3-inch paddle.

5. Flow rates for a 6-inch paddle.

inch 1 1/4 1 1/2 2 2 1/2 3 4 5 6 8 Pipe Size

mm 32 (2) 38 (2) 51 63 (3) 76 102 (4) 127 (4) 153 (4) 204 (5)

gpm 5.8 7.5 13.7 18.0 27.5 65.0 125.0 190.0 205.0 Lpm 1.3 1.7 3.1 4.1 6.2 14.8 28.4 43.2 46.6 gpm 3.7 5.0 9.5 12.5 19.0 50.0 101.0 158.0 170.0

gpm 13.3 19.2 29.0 34.5 53.0 128.0 245.0 375.0 415.0 Lpm 3.0 4.4 6.6 7.8 12.0 29.1 55.6 85.2 94.3 gpm 12.5 18.0 27.0 32.0 50.0 122.0 235.0 360.0 400.0

Water Connections

The unit has 3-inch holes for the chilled water piping to enter the unit. The connections are made to the evaporator water connections located within the unit. Chilled water piping within the unit must be insulated.

Refrigerant Charge

All units are designed for R-22 or R-407C and are shipped with an operating charge. The operating charge for each unit is shown in the Physical Data Tables on pages 16 and 17.

Unit Component Location

Chilled Water

Inlet Connection

Chilled Water

Outlet Connection

Evaporator

Control Panel

Tandem Scroll Compressors

Charging Valve

Solenoid Valve, Expansion Valve

Optional Hot Gas Bypass Valve Filter Drier

IOMM AGZB1 AGZ 010B through 034B 9

Glycol Solutions

The use of glycol antifreeze solutions will decrease unit capacity and increase the pressure drop through the cooler. See Product Manual Catalog ACZAGZB1 for specific ratings and correction factors.

CAUTION

Do not use automotive grade antifreeze. Industrial grade glycols must be used. Automotive antifreeze contains inhibitors that will cause plating on the copper tubes within the chiller evaporator. The type, storage, disposal, and handling of glycol used must be consistent with local codes.

Evaporator Water Flow and Pressure Drop

Evaporator flow rate must fall between the minimum and maximum values shown in the evaporator pressure drop curve, Figure 6. Flow rates outside of these limits result in a chilled water Delta-T outside the operating range of the controller.

Measure the chilled water pressure drop through the evaporator at field-installed pressure taps. It is important not to include the effect of valves or strainers in these readings.

Do not vary the chilled water flow through the evaporator while the compressors are operating.

10 AGZ 010B through 034B IOMM AGZB1

Figure 6, Evaporator Water Pressure Drop Curves

AGZ 020

AGZ 025

AGZ 029

AGZ 034

AGZ 010

AGZ 017

AGZ 013

Minimum Flow Nominal Flow Maximum Flow

AGZ

Model

010

013

017

020

025

029

034

Flow Rate

gpm L/s ft. kPa gpm L/s ft. kPa gpm L/s ft. kPa

15.0 0.9 2.4 7.1 24.0 1.5 5.8 17.3 40.0 2.5 15.2 45.5

19.5 1.2 1.5 4.5 31.2 2.0 3.7 11.0 52.0 3.3 9.6 28.9

24.0 1.5 1.7 5.0 38.4 2.4 4.1 12.2 64.0 4.0 10.7 32.1

30.0 1.9 2.3 6.8 48.0 3.0 5.6 16.7 80.0 5.0 14.5 43.4

34.5 2.2 1.8 5.3 55.2 3.5 4.3 13.0 92.0 5.8 11.4 34.3

40.7 2.6 1.7 5.0 65.0 4.1 4.0 12.1 108.4 6.8 10.9 32.6

49.8 3.1 1.6 4.7 79.7 5.0 3.9 11.7 132.8 8.4 10.4 31.2

Pressure

Drop

Flow Rate

Pressure

Drop

Flow Rate

Pressure

Drop

IOMM AGZB1 AGZ 010B through 034B 11

R-407C Units

AGZ chillers are available with R-407C refrigerant as non-ARI certified units. R-407C is a zeotropic blend of three compounds, and as such exhibits the characteristic of glide. It does not behave as one substance like R-22 does. Glide is the difference (in degrees F) between the beginning and end phase-change process in either the evaporator or condenser. During these processes, different ratios of the refrigerant’s components change phase from the beginning to the end of the process. The following functions, conditions and settings will differ from units charged with R-22.

1. Different physical data and electrical data

2. Polyolester lubricants are used instead of mineral oil.

3. The saturated pressure/temperature relationship

4. Control and alarm settings

5. Charging procedures

1. Lubrication. The units are factory-charged with polyoester (POE) lubricant and one of the

following lubricants must be used if lubricant is to be added to the system:

POEs are very hygroscopic and will quickly absorb moisture if exposed to air. Pump the lubricant into the unit through a closed transfer system. Avoid overcharging the unit.

Copeland Ultra 22 CC Mobil EAL Arctic 22 CC ICI EMKARATE RL RL 32CF

2. Pressure/temperature relationship. See Table 3 on page 13 for the saturated pressure-

temperature chart. Due to refrigerant glide, use the following procedures for superheat and subcooling measurement.

To determine superheat, only vapor must be present at the point of measurement, no liquid. Use the temperature reading, the pressure reading and the Saturated P/T Chart. If the pressure is measured at 78 psig, the chart shows the saturated vapor temperature to be

50.6°F. If the temperature is measured at 60°F, the superheat is 9.4 degrees F.

To determine subcooling, only liquid must be present, no vapor. Use the temperature reading, the pressure reading and the Saturated P/T Chart. If the pressure is measured at 250 psig, the chart shows the saturated liquid temperature to be 108.2°F. If the temperature is measured at 98°F, the subcooling is 10.2 degrees F.

The P/T relationship between R-407C and R-22 is similar enough to allow the use of R-22 expansion valves. The valves may be marked as “R-22’ or “R-22/R-407C”.

3. Control and alarm settings. The software that controls the operation of the unit is factory-

set for operation with R-407C, taking into account that the pressure/temperature relationship differs from R-22. The software functionality is the same for either refrigerant.

4. Charging procedure. The units are factory-charged with R-407C. Use the following

procedure if recharging in the field is necessary:

Whether topping off a charge or replacing the circuit’s entire charge, always remove the refrigerant from the charging vessel as a liquid. Many of the cylinders for the newer refrigerants have a dip tube so that liquid is drawn off when the cylinder is in the upright position. Do not vapor charge out of a cylinder unless the entire contents will be charged into the system.

With the system in a 250-micron or lower vacuum, liquid can be charged into the high side. Initially charge about 80 percent of the system total charge.

12 AGZ 010B through 034B IOMM AGZB1

Start the system and observe operation. Use standard charging procedures (liquid only) to top off the charge.

It may be necessary to add refrigerant through the compressor suction. Because the refrigerant leaving the cylinder must be a liquid, exercise care to avoid damage to the compressor. A sight glass can be connected between the charging hose and the compressor. It can be adjusted to have liquid leave the cylinder and vapor enter the compressor.

Table 3, R-407C Pressure/Temperature Chart

Pressure

(PSIG)

20 -10.7 1.5 150 74.8 84.9 22 -8.2 4.0 155 76.8 86.8 24 -5.7 6.4 160 78.7 88.7 26 -3.4 8.7 165 80.6 90.5 28 -1.1 11.0 170 82.5 92.3 30 1.1 13.1 175 84.3 94.0 32 3.2 15.2 180 86.1 95.8 34 5.3 17.2 185 87.8 97.5 36 7.3 19.2 190 89.6 99.1 38 9.2 21.0 195 91.3 100.7 40 11.1 22.9 200 92.9 102.3 42 12.9 24.7 205 94.6 103.9 44 14.7 26.4 210 96.2 105.4 46 16.4 28.1 215 97.7 107.0 48 18.1 29.7 220 99.3 108.4 50 19.7 31.3 225 100.8 109.9 52 21.3 32.9 230 102.3 111.4 54 22.9 34.4 235 103.8 112.8 56 24.4 35.9 240 105.3 114.2 58 25.9 37.4 245 106.7 115.6 60 27.4 38.8 250 108.2 116.9 62 28.8 40.2 255 109.6 118.2 64 30.2 41.6 260 111.0 119.6 66 31.6 43.0 265 112.3 120.9 68 33.0 44.3 270 113.7 122.1 70 34.3 45.6 275 115.0 123.4 72 35.6 46.9 280 116.3 124.7 74 36.9 48.1 285 117.6 125.9 76 38.2 49.3 290 118.9 127.1 78 39.4 50.6 295 120.2 128.3 80 40.6 51.8 300 121.4 129.5 82 41.9 52.9 305 122.7 130.7 84 43.0 54.1 310 123.9 131.8 86 44.2 55.2 315 125.1 133.0 88 45.4 56.3 320 126.3 134.1 90 46.5 57.4 325 127.5 135.2 92 47.6 58.5 330 128.7 136.3 94 48.7 59.6 335 129.8 137.4 96 49.8 60.7 340 131.0 138.5

98 50.9 61.7 345 132.1 139.6 100 51.9 62.7 350 133.2 140.6 105 54.5 65.2 355 134.3 141.7 110 57.0 67.7 360 135.4 142.7 115 59.5 70.0 365 136.5 143.7 120 61.8 72.3 370 137.6 144.7 125 64.1 74.6 375 138.7 145.7 130 66.4 76.7 380 139.8 146.7 135 68.5 78.8 385 140.8 147.7 140 70.7 80.9 390 141.8 148.7 145 72.8 82.9 395 142.9 149.6

Liquid Temp

(°F)

Vapor Temp

(°F)

Pressure

(PSIG)

Liquid Temp

(°F)

Vapor Temp

(°F)

IOMM AGZB1 AGZ 010B through 034B 13

Control Layout and Operation

Control Center

All electrical controls are enclosed in a weatherproof control center with tool-locked, hinged access doors. The left-hand section contains the microprocessor controller and control input and output terminals. All high-voltage components are located on the right side of the panel.

ON/OFF Switch

MicroTech II

Controller

SpeedTrol Location

Field Connection

Terminals

Start-up and Shutdown

Pre Start-up

1. The chilled-water system should be flushed and cleaned. Proper water treatment is required

to prevent corrosion and organic growth.

2. Open all electric disconnects and check all electric connections for tightness.

3. Inspect all water piping for flow direction and correct connections at the evaporator.

4. Verify thermostat water temperature sensor is installed in the leaving water line (supply to

building). On all AGZ units the sensor well and sensor are factory mounted.

5. Check compressor oil level. The oil level should be visible in the oil sight glass.

6. Check voltage of the unit power supply and make certain voltage is within ±10% of

nameplate rating. Check unit power supply wiring for proper ampacity and a minimum insulation temperature of 75°C. Check for proper phasing using a phase sequence meter.

7. Verify all mechanical and electrical inspections have been completed according to local

codes.

8. Open control stop switch S1(off). Turn on the main power and control disconnect switches.

This will energize crankcase heaters. Wait at least 24 hours before starting up unit.

9. Open all water flow valves and start the chilled water pump. Check all piping for leaks and

vent the air from the evaporator as well as from the system piping. Flush the evaporator and system piping to obtain clean, noncorrosive water in the evaporator.

Control Transformer

24-Volt Trans.

Non-Fused Disc.

Power Block

Fan Contactors

Fan Protection

Compressor Contactors

Start-up

1. Set temperature controller to the desired chilled water temperature. Set the chilled water

Delta-T.

14 AGZ 010B through 034B IOMM AGZB1

2. Start auxiliary equipment by turning on the following: time clock (if present), ambient

thermostat and/or remote on/off switch, chilled water pump.

3. If the controller calls for cooling, the unit will begin the start-up sequence.

4. After running the unit for a short time, check the oil level in the compressor (1/4 to 1/3

of the glass), rotation of fans, and flashing in refrigerant sight glass.

5. Verify superheat temperature is at the factory setting of 8 to 12 degrees F (4.4 to 6.7

degrees C).

6. After system performance has stabilized, complete the current AGZ Start-Up Form

(obtainable from the local McQuay sales office) to establish inception of warranty benefits. Return the form to McQuay International through your sales representative.

Sequence of Operation

Start-Up

With the control circuit power on, 115V power is applied through the control circuit fuse F1 to the compressor crankcase heaters, the compressor motor protections and the primary of the 24V control circuit transformer. The 24V transformer provides power to the microprocessor controller.

When a remote time clock, manual switch, or the unit controller turns on the chilled water pump, the flow switch closes and satisfies the flow requirement. If the chilled water temperature is above the stage-on temperature, and all equipment protection devices are closed, the unit will start. The controller will operate the unit in response to the leaving chiller water temperature or reset signals that may be present.

Equipment Protection Alarms

The following conditions will shut down the unit and activate the alarm circuit:

• No evaporator water flow • Low evaporator pressure

• High condenser pressure • Motor protection system

• Phase voltage protection (Optional) • Outside ambient temperature

• Evaporator freeze protection • Sensor failures

The following alarms will limit unit operation:

• Condenser pressure stage down, unloads unit at high discharge pressures

• Low ambient lockout, shuts off unit at low ambient temperatures

• Low evaporator pressure hold, holds stage #1 until pressure rises

• Low evaporator pressure unload, shuts off stage #2

Unit Enable Selection

Enables unit operation from local keypad, digital input, or Building Automation System.

Unit Mode Selection

Selects standard cooling, ice, glycol, or test operation mode.

Condenser fan control

Control of condenser fans is provided by the MicroTech II controller. The control steps condenser fans based on discharge pressure.

Shutdown

As the leaving water control is satisfied, it will stage off the lag compressor unloading the unit. The second stage will de-energize the liquid line solenoid valve SV1 and shut off the lead compressor. The compressor crankcase heaters will energize when the compressors shut off, keeping the small amount of refrigerant in the plate heat exchanger from migrating to the compressor. See page 56 for detailed explanation of compressor staging.

IOMM AGZB1 AGZ 010B through 034B 15

Physical Data

AGZ-BS, R-22/R-407C

Table 4, Physical Data, AGZ 010BS through 017BS, Packaged, R-22/R-407C

PHYSICAL DATA

BASIC DATA

Unit Capacity @ ARI Conditions (1), Tons (kW) 10.0 (36.2) 13.7 (48.2) 15.8 (55.6)

Number Of Refrigerant Circuits 1 1 1

Unit Operating Charge, R-22 and R-407C, Lb. (kg) 22.0 (10.0) 24.0 (10.9) 31.0 (14.1)

Cabinet Dimensions, LxWxH, In. 73.6 x 46.3 x 50.8 73.6 x 46.3 x 50.8 73.6 x 46.3 x 50.8

Cabinet Dimensions, LxWxH, (mm) (1869) x (1176) x (1289) (1869) x (1176) x (1289) (1869) x (1176) x (1289)

Unit Operating Weight, Lb. (kg) 1095 (498) 1190 (541) 1300 (591)

Unit Shipping Weight, Lb. (kg) 1085 (493) 1170 (532) 1280 (582) Add'l Weight If Copper Finned Coils, Lb. (kg)

R-22 and [R-407C]

COMPRESSORS

Type Scroll Scroll Scroll

Nominal Horsepower 6.0 / 6.0 7.5 / 7.5 9.0 / 9.0

Oil Charge Per Compressor of a Tandem Set, oz. (g) 60 (1701) 85 (2410) 110 (3119)

CAPACITY REDUCTION STEPS - PERCENT OF COMPRESSOR DSPLACEMENT

Standard Staging 0 – 50 – 100 0 – 50 – 100 0 – 50 – 100

CONDENSERS - HIGH EFFICIENCY FIN AND TUBE TYPE WITH INTEGRAL SUBCOOLING

Coil Face Area, One of Two Sides, Sq. Ft. (M2) 30.3 (2.8) 30.3 (2.8) 30.3 (2.8)

Finned Height x Finned Length, In. 84 x 52 84 x 52 84 x 52

Finned Height x Finned Length, (mm) (2134) x (1321) (2134) x (1321) (2134) x (1321)

Fins Per Inch x Rows Deep: R-22 and [R-407C] 16 x 2 [16 x 2] 16 x 2 [16 x 2] 16 x 3 [16 x 3]

Pumpdown Capacity Lb. (kg) 35.3 (16.0) 35.3 (16.0) 52.9 (24.0)

CONDENSER FANS - DIRECT DRIVE PROPELLER TYPE

Number Of Fans - Fan Diameter, In. (mm) 2 – 26 (660) 2 – 26 (660) 2 – 26 (660)

Number Of Motors - HP (kW) 2 – 1.0 (0.75) 2 – 1.0 (0.75) 2 – 1.0 (0.75)

Fan And Motor RPM, 60 Hz 1140 1140 1140

60 Hz Total Unit Airflow, CFM (l/s) 13950 (6584) 13950 (6584) 12000 (5664)

DIRECT EXPANSION EVAPORATOR - BRAZED PLATE-TO-PLATE

Connection Size Victaulic, In. (mm) 2 (51) 2 (51) 2 (51)

Water Volume, Gallons (L) .94 (3.6) 1.66 (6.3) 2.00 (7.6)

Maximum Refrigerant Working Pressure, psig (kPa) 450 (3103) 450 (3103) 450 (3103)

Maximum Water Pressure, psig (kPa) 350 (2413) 350 (2413) 350 (2413)

NOTE: Nominal capacity based on 95°F ambient air and 54°F/44°F water range.

010B 013B 017B

176 (80.0)

[176 (80.0)]

AGZ MODEL NUMBER

176 (80.0)

[176 (80.0)]

264 (120.0)

[264 (120.0)]

16 AGZ 010B through 034B IOMM AGZB1

Table 5, Physical Data, AGZ 020BS through 034BS, Packaged, R-22/R-407c

PHYSICAL DATA

BASIC DATA

Unit Capacity @ ARI Conditions (1), Tons (kW) 20.6 (72.4) 22.7 (79.8) 27.7 (97.5) 34.0 (119.5)

Number Of Refrigerant Circuits 1 1 1 1 Unit Operating Charge, R-22 and [R-407C],

Lb. (kg) Cabinet Dimensions, LxWxH, In. 106.2x 46.3 x 50.8 106.2x 46.3 x 50.8 106.2x 46.3 x 58.8 106.2x 46.3 x 58.8

Cabinet Dimensions, LxWxH, (mm)

Unit Operating Weight, Lbs. (kg) 1590 (723) 1635 (743) 1830 (832) 2315 (1052)

Unit Shipping Weight, Lbs. (kg) 1570 (714) 1610 (732) 1800 (818) 2270 (1032) Add'l Weight If Copper Finned Coils, Lb. (kg)

R-22 and [R-407C]

COMPRESSORS

Type Scroll Scroll Scroll Scroll

Nominal Horsepower 12.0 / 12.0 13.0 / 13.0 15.0 / 15.0 20.0 / 20.0 Oil Charge Per Compressor of a Tandem Set,

oz. (g)

CAPACITY REDUCTION STEPS - PERCENT OF COMPRESSOR DISPLACEMENT

Standard Staging 0 –50 - 100 0 – 50 – 100 0 – 50 – 100 0 – 50 – 100

CONDENSERS - HIGH EFFICIENCY FIN AND TUBE TYPE WITH INTEGRAL SUBCOOLING

Coil Face Area, One of Two Sides, Sq. Ft. (M2) 49.0 (4.6) 49.0 (4.6) 58.3 (5.4) 58.3 (5.4)

Finned Height x Finned Length, In. 84 x 84 84 x 84 100 x 84 100 x 84

Finned Height x Finned Length, (mm) (2134) x (2134) (2134) x (2134) (2545 ) x (2134) (2545 ) x (2134)

Fins Per Inch x Rows Deep: R22 and [R407C] Pumpdown Capacity, R-22 and [R-407C]

Lb. (kg)

CONDENSER FANS - DIRECT DRIVE PROPELLER TYPE

Number Of Fans - Fan Diameter, In. (mm) 3 – 26 (660) 3 – 26 (660) 3 – 26 (660) 3 – 26 (660)

Number Of Motors - HP (kW) 3 – 1.0 (0.75) 3 – 1.0 (0.75) 3 – 1.0 (0.75) 3 – 1.0 (0.75)

Fan And Motor RPM, 60 Hz 1140 1140 1140 1140

60 Hz Total Unit Airflow, CFM (l/s) 20925 (9877) 20925 (9877) 19800 (9346) 19800 (9346)

DIRECT EXPANSION EVAPORATOR - BRAZED PLATE-TO-PLATE

Connection Size Victaulic, In. (mm) 2 (51) 2 (51) 2 (51) 2 (51)

Water Volume, Gallons (L) 2.16 (8.2) 3.05 (11.5) 4.00 (15.1) 5.55 (21.0)

Max. Refrigerant Working Pressure, psig (kPa) 450 (3103) 450 (3103) 450 (3103) 450 (3103)

Maximum Water Pressure, psig (kPa) 350 (2413) 350 (2413) 350 (2413) 350 (2413)

NOTE: Nominal capacity based on 95°F ambient air and 54°F/44°F water range.

020B 025B 029B 034B

34.0 (15.4)

[38.0 (17.3)]

(2697) x (1176) x

(1289)

284 (129)

[426 (194)]

110 (3119) 110 (3119) 110 (3119) 158 (4479)

16 x 2 [16 x 3] 16 x 3 [16 x 3] 16 x 3 [16 x 3] 16 x 3 [16 x 3]

56.9 (25.9)

[85.4 (38.8)]

AGZ MODEL NUMBER

42.0 (19.1) 47.0 (21.3) 50.0 (22.7)

(2697) x (1176) x

(1289)

426 (194)

[426 (194)]

85.4 (38.8) 101.6 (46.2) 101.6 (46.2)

(2697) x (1176) x

(1493)

508 (231)

[508 (231)]

(2697) x (1176) x

(1493)

508 (231)

[508 (231)]

IOMM AGZB1 AGZ 010B through 034B 17

AGZ-BM, R-22/R-407C

Table 6, Physical Data, AGZ 010BM through 017BM, Remote Evaporator, R-22/R-407C

PHYSICAL DATA

BASIC DATA

Unit Capacity @ ARI Conditions (1), Tons (kW) 10.0 (36.2) 13.7 (48.2) 15.8 (55.6)

Number Of Refrigerant Circuits 1 1 1

Unit Operating Charge, R-22 and[R-407C, Lb. (kg) 13 (5.9) 14 (5.3) 17 (7.7)

Cabinet Dimensions, LxWxH, In. 73.6 x 46.3 x 50.8 73.6 x 46.3 x 50.8 73.6 x 46.3 x 50.8

Cabinet Dimensions, LxWxH, (mm) (1869) x (1176) x (1289) (1869) x (1176) x (1289) (1869) x (1176) x (1289)

Unit Operating Weight, Lb. (kg) 950 (431) 1276 (579) 1278 (580)

Unit Shipping Weight, Lb. (kg) 1025 (465) 1350 (613) 1363 (619) Add'l Weight If Copper Finned Coils, Lb. (kg)

R-22 and [R-407C]

COMPRESSORS

Type Scroll Scroll Scroll

Nominal Horsepower 6.0 / 6.0 7.5 / 7.5 9.0 / 9.0

Oil Charge Per Compressor of a Tandem Set, oz. (g) 60 (1701) 85 (2410) 110 (3119)

CAPACITY REDUCTION STEPS - PERCENT OF COMPRESSOR DSPLACEMENT

Standard Staging 0 – 50 – 100 0 – 50 – 100 0 – 50 – 100

CONDENSERS - HIGH EFFICIENCY FIN AND TUBE TYPE WITH INTEGRAL SUBCOOLING

Coil Face Area, One of Two Sides, Sq. Ft. (M2) 30.3 (2.8) 30.3 (2.8) 30.3 (2.8)

Finned Height x Finned Length, In. 84 x 52 84 x 52 84 x 52

Finned Height x Finned Length, (mm) (2134) x (1321) (2134) x (1321) (2134) x (1321)

Fins Per Inch x Rows Deep: R-22 and [R-407C] 16 x 2 [16 x 2] 16 x 2 [16 x 2] 16 x 3 [16 x 3]

Pumpdown Capacity Lb. (kg) 35.3 (16.0) 35.3 (16.0) 52.9 (24.0)

CONDENSER FANS - DIRECT DRIVE PROPELLER TYPE

Number Of Fans - Fan Diameter, In. (mm) 2 – 26 (660) 2 – 26 (660) 2 – 26 (660)

Number Of Motors - HP (kW) 2 – 1.0 (0.75) 2 – 1.0 (0.75) 2 – 1.0 (0.75)

Fan And Motor RPM, 60 Hz 1140 1140 1140

60 Hz Total Unit Airflow, CFM (l/s) 13950 (6584) 13950 (6584) 12000 (5664)

REMOTE DIRECT EXPANSION EVAPORATOR - BRAZED PLATE-TO-PLATE

Water Connection Size Victaulic, In. (mm) 2 (51) 2 (51) 2 (51)

Water Volume, Gallons (L) .94 (3.6) 1.66 (6.3) 2.00 (7.6)

Liquid Line Conn. Braze, inches 1.125 1.125 1.125

Suction Line Conn. Braze, Inches 2.125 2.125 2.125

Temperature Sensor Conn. NPT, Inches 0.75 0.75 0.75

Dry Weight, lbs (kg) 50 (22) 75 (34) 87 (39)

Operating Weight, lbs (kg) 58 (26) 88 (40) 109 (49)

Maximum Refrigerant Working Pressure, psig (kPa) 450 (3103) 450 (3103) 450 (3103)

Maximum Water Pressure, psig (kPa) 450 (3103) 450 (3103) 450 (3103)

Vent and Drain Conn. Field Field Field

NOTE: Nominal capacity based on 95°F ambient air and 54°F/44°F water range and does not take field-installed lines into account.

010B 013B 017B

176 (80.0)

[176 (80.0)]

AGZ MODEL NUMBER

176 (80.0)

[176 (80.0)]

264 (120.0)

[264 (120.0)]

18 AGZ 010B through 034B IOMM AGZB1

Table 7, Physical Data, AGZ 020BM through 034BmS, Remote Evaporator, R-22/R-407c

PHYSICAL DATA

BASIC DATA

Unit Capacity @ ARI Conditions (1), Tons (kW) 20.6 (72.4) 22.7 (79.8) 27.7 (97.5) 34.0 (119.5)

Number Of Refrigerant Circuits 1 1 1 1 Unit Operating Charge, R-22 and [R-407C],

Lb. (kg) Cabinet Dimensions, LxWxH, In. 106.2x 46.3 x 50.8 106.2x 46.3 x 50.8 106.2x 46.3 x 58.8 106.2x 46.3 x 58.8

Cabinet Dimensions, LxWxH, (mm)

Unit Operating Weight, Lbs. (kg) 1459 (662) 1478 (671) 1622 (737) 1817 (825)

Unit Shipping Weight, Lbs. (kg) 1558 (707) 1576 (716) 1719 (780) 1914 (869) Add'l Weight If Copper Finned Coils, Lb. (kg)

R-22 and [R-407C]

COMPRESSORS

Type Scroll Scroll Scroll Scroll

Nominal Horsepower 12.0 / 12.0 13.0 / 13.0 15.0 / 15.0 20.0 / 20.0 Oil Charge Per Compressor of a Tandem Set,

oz. (g)

CAPACITY REDUCTION STEPS - PERCENT OF COMPRESSOR DISPLACEMENT

Standard Staging 0 –50 - 100 0 – 50 – 100 0 – 50 – 100 0 – 50 – 100

CONDENSERS - HIGH EFFICIENCY FIN AND TUBE TYPE WITH INTEGRAL SUBCOOLING

Coil Face Area, One of Two Sides, Sq. Ft. (M2) 49.0 (4.6) 49.0 (4.6) 58.3 (5.4) 58.3 (5.4)

Finned Height x Finned Length, In. 84 x 84 84 x 84 100 x 84 100 x 84

Finned Height x Finned Length, (mm) (2134) x (2134) (2134) x (2134) (2545 ) x (2134) (2545 ) x (2134)

Fins Per Inch x Rows Deep: R22 and [R407C] Pumpdown Capacity, R-22 and [R-407C]

Lb. (kg)

CONDENSER FANS - DIRECT DRIVE PROPELLER TYPE

Number Of Fans - Fan Diameter, In. (mm) 3 – 26 (660) 3 – 26 (660) 3 – 26 (660) 3 – 26 (660)

Number Of Motors - HP (kW) 3 – 1.0 (0.75) 3 – 1.0 (0.75) 3 – 1.0 (0.75) 3 – 1.0 (0.75)

Fan And Motor RPM, 60 Hz 1140 1140 1140 1140

60 Hz Total Unit Airflow, CFM (l/s) 20925 (9877) 20925 (9877) 19800 (9346) 19800 (9346)

REMOTE DIRECT EXPANSION EVAPORATOR - BRAZED PLATE-TO-PLATE

Connection Size Victaulic, In. (mm) 2 (51) 2 (51) 2 (51) 2 (51)

Water Volume, Gallons (L) 2.16 (8.2) 3.05 (11.5) 4.00 (15.1) 5.55 (21.0)

Liquid Line Conn. Braze, inches 1.125 1.125 1.375 1.375

Suction Line Conn. Braze, Inches 2.125 2.125 2.125 2.125

Temperature Sensor Conn. NPT, Inches 0.75 0.75 0.75 0.75

Dry Weight, lbs (kg) 92 (42) 124 (56) 156 (71) 211 (96)

Operating Weight, lbs (kg) 110 (50) 148 (67) 188 (85) 255 (116)

Max. Refrigerant Working Pressure, psig (kPa) 450 (3103) 450 (3103) 450 (3103) 450 (3103)

Maximum Water Pressure, psig (kPa) 350 (2413) 350 (2413) 350 (2413) 350 (2413)

Drain and Vent Connections Field Field Field Field

NOTE: Nominal capacity based on 95°F ambient air and 54°F/44°F water range and does not take field-installed lines into account.

020B 025B 029B 034B

34.0 (15.4)

[38.0 (17.3)]

(2697) x (1176) x

(1289)

284 (129)

[426 (194)]

110 (3119) 110 (3119) 110 (3119) 158 (4479)

16 x 2 [16 x 3] 16 x 3 [16 x 3] 16 x 3 [16 x 3] 16 x 3 [16 x 3]

56.9 (25.9)

[85.4 (38.8)]

AGZ MODEL NUMBER

42.0 (19.1) 47.0 (21.3) 50.0 (22.7)

(2697) x (1176) x

(1289)

426 (194)

[426 (194)]

85.4 (38.8) 101.6 (46.2) 101.6 (46.2)

(2697) x (1176) x

(1493)

508 (231)

[508 (231)]

(2697) x (1176) x

(1493)

508 (231)

[508 (231)]

IOMM AGZB1 AGZ 010B through 034B 19

Electrical Data

Field Wiring

Wiring must comply with all applicable codes and ordinances. Warranty is void if wiring is not in accordance with specifications. Copper wire is required for all power lead terminations at the unit.

AGZ 010A through AGZ 034A units have single point power connection. A single field supplied fused disconnect is required. The control transformer is factory mounted.

If the evaporator heater is on a separate disconnect switch from the main unit power supply, the unit may be shut down without defeating the freeze protection provided by the evaporator heater.

R-22 data is located on pages 21 through 22, R-407C data in on pages 23 through 24.

R-22

Table 8, Electrical Data Single Point, R-22

AGZ Unit Size

010B

013B

017B

020B

025B

029B

034B

See "Electrical Notes" on page 26.

Volts

208 56 3 6 AWG 1 1.00 (25)

230 54 3 6 AWG 1 1.00 (25)

460 26 3 10 AWG

575 22 3 10 AWG

208 77 3 4 AWG 1 1.00 (25)

230 77 3 4 AWG 1 1.00 (25)

460 39 3 8 AWG 1 1.00 (25)

575 30 3 10 AWG

208 82 3 4 AWG 1 1.00 (25)

230 80 3 4 AWG 1 1.00 (25)

460 41 3 8 AWG 1 1.00 (25)

575 33 3 10 AWG

208 113 3 2 AWG 1 1.25 (32)

230 113 3 2 AWG 1 1.25 (32)

460 50 3 8 AWG 1 1.00 (25)

575 42 3 8 AWG 1 1.00 (25)

208 126 3 1 AWG 1 1.25 (32)

230 126 3 1 AWG 1 1.25 (32)

460 58 3 6 AWG 1 1.00 (25)

575 50 3 8 AWG 1 1.00 (25)

208 138 3 1/0 AWG

230 138 3 1/0 AWG

460 69 3 4 AWG 1 1.00 (25)

575 57 3 6 AWG 1 1.00 (25)

208 182 3 3/0 AWG

230 182 3 3/0 AWG

460 78 3 4 AWG 1 1.00 (25)

575 63 3 6 AWG 1 1.00 (25)

Minimum

Circuit

Ampacity

(MCA)

Field Wire

Quantity

Power Supply

Wire

Gauge

75C

Quantity

Hub (Conduit

Connection)

Nominal

Size

In. (mm)

1 1.00 (25)

1 1.50 (38)

1 2.00 (51)

Field Fuse

or Breaker Size

Recommended Maximum

70 70

60 70

30 30

25 25

90 100

45 50

35 40

110 110

90 100

50 50

40 40

125 150

60 60

50 50

150 150

70 70

60 60

175 175

80 90

70 70

250 250

90 100

70 80

20 AGZ 010B through 034B IOMM AGZB1

Table 9, Compressor and Condenser Fan Motor Amp Draw, R-22

AGZ Unit Size

010B

013B

017B

020B

025B

029B

034B

Volts

208 19.4 19.4 5.8 2 21.4 156 156

230 18.6 18.6 5.8 2 23.7 156 156

460 9.0 9.0 2.8 2 10.7 75 75

575 7.4 7.4 2.5 2 11.0 54 54

208 28.8 28.8 5.8 2 21.4 195 195

230 28.8 28.8 5.8 2 23.7 195 195

460 14.7 14.7 2.8 2 10.7 95 95

575 10.8 10.8 2.5 2 11.0 80 80

208 31.2 31.2 5.8 2 21.4 225 225

230 30.1 30.1 5.8 2 23.7 225 225

460 15.5 15.5 2.8 2 10.7 114 114

575 12.1 12.1 2.5 2 11.0 80 80

208 42.3 42.3 5.8 3 21.4 245 245

230 42.3 42.3 5.8 3 23.7 245 245

460 18.2 18.2 2.8 3 10.7 125 125

575 14.9 14.9 2.5 3 11.0 100 100

208 48.1 48.1 5.8 3 21.4 300 300

230 48.1 48.1 5.8 3 23.7 300 300

460 21.8 21.8 2.8 3 10.7 150 150

575 18.6 18.6 2.5 3 11.0 109 109

208 53.2 53.2 5.8 3 21.4 340 340

230 53.2 53.2 5.8 3 23.7 340 340

460 26.5 26.5 2.8 3 10.7 173 173

575 21.7 21.7 2.5 3 11.0 132 132

208 73.1 73.1 5.8 3 21.4 505 505

230 73.1 73.1 5.8 3 23.7 505 505

460 30.5 30.5 2.8 3 10.7 225 225

575 24.4 24.4 2.5 3 11.0 180 180

See "Electrical Notes" on page 26.

Rated Load Amps Locked Rotor Amps

Compressors Compressors

No. 1 No. 2

Fan

Motor

(Each)

No. of

Fans

Fan

Motor

(Each)

Across-The-Line

No. 1 No. 2

IOMM AGZB1 AGZ 010B through 034B 21

Table 10, Field Wiring Data, R-22

AGZ

Unit Size

010B

013B

017B

020B

025B

029B

Standard Power Block Terminal

Volts

Maximum

Terminal Amps

208 175

230 175

460 175

575 175

208 175

230 175

460 175

575 175

208 175

230 175

460 175

575 175

208 175

230 175

460 175

575 175

208 175

230 175

460 175

575 175

208 175

230 175

460 175

575 175

Wiring to

Optional Disconnect Switch

Connector Wire

Range

(Copper Wire Only)

Disconnect

Size

14 AWG – 2/0 60

14 AWG – 2/0 60 14 AWG – 1 AWG 80 10 AWG - 1/0

14 AWG – 2/0 60 14 AWG – 1 AWG 40 10 AWG - 1/0

14 AWG – 2/0 60 14 AWG – 1 AWG 35 10 AWG - 1/0

14 AWG – 2/0 100

14 AWG – 2/0 60 14 AWG – 1 AWG 60 10 AWG - 1/0

14 AWG – 2/0 60 14 AWG – 1 AWG 50 10 AWG - 1/0

14 AWG – 2/0 100

14 AWG – 2/0 60 14 AWG – 1 AWG 70 10 AWG - 1/0

14 AWG – 2/0 60 14 AWG – 1 AWG 50 10 AWG - 1/0

14 AWG – 2/0 125

14 AWG – 2/0 60 14 AWG – 1 AWG 80 10 AWG - 1/0

14 AWG – 2/0 60 14 AWG – 1 AWG 70 10 AWG - 1/0

14 AWG – 2/0 225

14 AWG – 2/0 100

14 AWG – 2/0 60

14 AWG – 2/0 225

14 AWG – 2/0 100

208 335 6 AWG – 400 kcmil

034B

230 335 6 AWG – 400 kcmil

460 175 14 AWG – 2/0

575 175 14 AWG – 2/0

NOTES:

1. High Interruptor or HSCCR Circuit Breakers are not available in these sizes

2. "Size" is the maximum amperage rating for the terminals or the main electrical device.

3. "Size" is the disconnect part number and not the amperage rating for the terminals or the main electrical device.

4. "Connection" is the range of wire sizes that the terminals on the electrical device will accept.

5. See page 26 for additional electrical notes.

225

100

Wiring to

Connector Wire

Range

(Copper Wire Only)

14 AWG – 1 AWG

8 AWG - 1/0

3 AWG – 3/0

3 AWG - 3/0

2 AWG - 4/0

8 AWG - 1/0

14 AWG – 1 AWG

2 AWG - 4/0

8 AWG - 1/0

2 AWG - 4/0

8 AWG - 1/0

Wiring to High Interrupt

or HSCCR Circuit Breaker

Max.

Amps

Connector Wire

(Copper Wire Only)

90 10 AWG - 1/0

125 3 AWG - 3/0

175 6 AWG - 350 kcmil

200 6 AWG - 350 kcmil

100 10 AWG - 1/0

80 10 AWG - 1/0

225 6 AWG - 350 kcmil

125 3 AWG - 3/0

90 10 AWG - 1/0

N/A Note 1

150 6 AWG - 350 kcmil

125 3 AWG - 3/0

Range

22 AGZ 010B through 034B IOMM AGZB1

R-407C

Table 11, Electrical Data, R-407C

AGZ Unit Size

010B

013B

017B

020B

025B

029B

034B

NOTE: See page 26 for all Electrical Data notes.

Volts

208

230

460

575

208

230

460

575

208

230

460

575

208

230

460

575

208

230

460

575

208

230

460

575

208

230

460

575

Minimum

Circuit

Ampacity

(MCA)

113

129

148

139

187

182

Field Wire

Quantity

Gauge

3 6 AW G 1 1.00 (25)

3 10 AWG

3 4 AW G 1 1.00 (25)

3 8 AW G 1 1.00 (25)

3 10 AWG

3 4 AW G

3 8 AW G 1 1.00 (25)

3 10 AWG

3 2 AW G 1 1.25 (32)

3 6 AW G 1 1.00 (25)

3 8 AW G 1 1.00 (25)

3 1 AW G 1 1.25 (32)

3 6 AW G

3 1/0 AWG

3 4 AW G 1 1.00 (25)

3 6 AW G 1 1.00 (25)

3 3/0 AWG

3 4 AW G

Power Supply

Hub (Conduit

Wire

Quantity

75C

Connection)

Nominal

Size

In. (mm)

1 1.00 (25)

1 1.50 (38)

1 2.00 (51)

1 1.00 (25)

Field Fuse

or Breaker Size

Recommended Maximum

70 70

60 70

30 35

25 25

90 100

45 50

35 40

110 110

90 100

50 50

40 40

125 150

60 60

50 50

150 175

70 80

60 60

175 200

175 175

80 100

80 80

250 250

100 110

100 100

IOMM AGZB1 AGZ 010B through 034B 23

Table 12, AGZ 010 034A, Compressor & Fan Motor Amps, R-407C

AGZ Unit Size

010B

013B

017B

020B

025B

029B

034B

NOTE: See page 26 for all Electrical Data notes.

Volts

208

230

460

575

208

230

460

575

208

230

460

575

208

230

460

575

208

230

460

575

208

230

460

575

208

230

460

575

Rated Load Amps Locked Rotor Amps

Compressors Compressors

No. 1 No. 2

20.3 20.3

18.6 18.6

9.2 9.2

7.4 7.4

28.8 28.8

14.7 14.7

10.8 10.8

31.2 31.2

30.1 30.1

15.5 15.5

12.1 12.1

42.3 42.3

18.6 18.6

14.6 14.6

49.4 49.4

23.1 23.1

19.2 19.2

57.9 57.9

53.8 53.8

28.2 28.2

22.4 22.4

75.0 75.0

73.1 73.1

34.0 34.0

28.8 28.8

F.L. Amps

Fan

Motor

(Each)

5.8 2 21.4 156 156

5.8 2 23.7 156 156

2.8 2 10.7 75 75

2.5 2 11.0 54 54

5.8 2 21.4 195 195

5.8 2 23.7 195 195

2.8 2 10.7 95 95

2.5 2 11.0 80 80

5.8 2 21.4 225 225

5.8 2 23.7 225 225

2.8 2 10.7 114 114

2.5 2 11.0 80 80

5.8 3 21.4 245 245

5.8 3 23.7 245 245

2.8 3 10.7 125 125

2.5 3 11.0 100 100

5.8 3 21.4 300 300

5.8 3 23.7 300 300

2.8 3 10.7 150 150

2.5 3 11.0 109 109

5.8 3 21.4 340 340

5.8 3 23.7 340 340

2.8 3 10.7 173 173

2.5 3 11.0 132 132

5.8 3 21.4 505 505

5.8 3 23.7 505 505

2.8 3 10.7 225 225

2.5 3 11.0 180 180

No. of

Fans

Fan

Motor

(Each)

Across-The-Line

No. 1 No. 2

24 AGZ 010B through 034B IOMM AGZB1

Table 13, Field Wiring Data, R-407C

AGZ

Volts

Unit Size

208

230

010B

460

575

208

230

013B

460

575

208

230

017B

460

575

208

230

020B

460

575

208

230

025B

460

575

208

230

029B

460

575

208

230

034B

460

575

NOTE:

1. High Interruptor or HSCCR Circuit Breakers are not available in these sizes

2. "Size" is the maximum amperage rating for the terminals or the main electrical device.

3. "Size" is the disconnect part number and not the amperage rating for the terminals or the main electrical device.

4. "Connection" is the range of wire sizes that the terminals on the electrical device will accept.

5. See page 26 for additional electrical notes.

Standard Power Block Terminal

Maximum

Terminal Amps

Wiring to

Connector Wire

Range

(Copper Wire Only)

175

335 6 AWG – 400 kcmil

175 14 AWG – 2/0

14 AWG – 2/0 60

14 AWG – 2/0 60 14 AWG – 1 AWG 80 10 AWG - 1/0

14 AWG – 2/0 60 14 AWG – 1 AWG 40 10 AWG - 1/0

14 AWG – 2/0 60 14 AWG – 1 AWG 35 10 AWG - 1/0

14 AWG – 2/0 100

14 AWG – 2/0 60 14 AWG – 1 AWG 60 10 AWG - 1/0

14 AWG – 2/0 60 14 AWG – 1 AWG 50 10 AWG - 1/0

14 AWG – 2/0 100

14 AWG – 2/0 60 14 AWG – 1 AWG 70 10 AWG - 1/0

14 AWG – 2/0 60 14 AWG – 1 AWG 50 10 AWG - 1/0

14 AWG – 2/0 125

14 AWG – 2/0 60 14 AWG – 1 AWG 80 10 AWG - 1/0

14 AWG – 2/0 60 14 AWG – 1 AWG 70 10 AWG - 1/0

14 AWG – 2/0 225

14 AWG – 2/0 100

14 AWG – 2/0 60

14 AWG – 2/0 225

14 AWG – 2/0 100

Optional Disconnect Switch

Disconnect

Size

225

100

Wiring to

Connector Wire

Range

(Copper Wire Only)

14 AWG – 1 AWG

8 AWG - 1/0

3 AWG – 3/0

3 AWG - 3/0

2 AWG - 4/0

8 AWG - 1/0

14 AWG – 1 AWG

2 AWG - 4/0

8 AWG - 1/0

2 AWG - 4/0

8 AWG - 1/0

Wiring to High Interrupt

or HSCCR Circuit Breaker

Max.

Amps

125 3 AWG - 3/0

175 6 AWG - 350 kcmil

200 6 AWG - 350 kcmil

100 10 AWG - 1/0

225 6 AWG - 350 kcmil

125 3 AWG - 3/0

N/A Note 1

150 6 AWG - 350 kcmil

125 3 AWG - 3/0

Connector Wire

(Copper Wire Only)

90 10 AWG - 1/0

80 10 AWG - 1/0

90 10 AWG - 1/0

Range

IOMM AGZB1 AGZ 010B through 034B 25

Notes for Electrical Data

1. Unit wire size ampacity (MCA) is equal to 125% of the largest compressor-motor RLA

plus 100% of RLA of all other loads in the circuit.

2. The control transformer is furnished and no separate 115V power supply is required.

3. If a separate 115V power supply is used for the control circuit, then the wire sizing

amps is 10 amps for all unit sizes.

4. Recommended power lead wire sizes for three conductors per conduit are based on

100% conductor ampacity in accordance with NEC. Voltage drop has not been included. Therefore, it is recommended that power leads be kept short. All terminal block connections must be made with copper wire.

5. “Recommended Fuse Sizes” are selected at approximately 175% of the largest

compressor RLA, plus 100% of the RLA of all other loads in the circuit.

6. “Maximum Fuse or breaker size” is selected at approximately 225% of the largest

compressor RLA, plus 100% of all other loads in the circuit.

7. The recommended power lead wire sizes are based on an ambient temperature of 86°F

(30°C). Ampacity correction factors must be applied for other ambient temperatures. Refer to the National Electrical Code Handbook.

8. Units must be electrically grounded according to national and local electrical codes.

Voltage Limitations:

Within ± 10 percent of nameplate rating

Important: Voltage unbalance not to exceed 2% with a resultant current unbalance of 6 to 10 times the voltage unbalance per NEMA MG-1, 1998 Standard. This is an important restriction that must be adhered to.

Notes for “Compressor and Condenser Fan Amp Draw”:

1. Compressor RLA values are for wiring sizing purposes only but may not reflect normal

operating current draw at rated capacity.

2. Fan motor FLA values are approximate fan motor amp values at rated voltage.

Notes for “Field Wiring Data”

1. Requires a single disconnect to supply electrical power to the unit. This power supply

must either be fused or use a circuit breaker.

2. All field wiring to unit power block or optional non-fused disconnect switch must be

copper.

3. All field wire size values given in table apply to 75°C rated wire per NEC.

26 AGZ 010B through 034B IOMM AGZB1

Figure 7, AGZ 010A through AGZ 034A, Typical Field Wiring Diagram

LABEL DWG. 330538401 REV.0B

UNIT MAIN

120

VAC

TB1

TB1-20

CONTROL

CIRCUIT

GND

ALARM BELL RELAY

FACTORY SUPPLIED ALARM

120 VAC

IF SEPARATE EVAPORATOR

BETWEEN TB1-5 AND TB1-6

120 VAC

CHW PUMP RELAY

4-20MA FOR

GND

ICE MODE

AUTO

MANUAL

ALARM BELL

ALARM BELL OPTION

COM

TB2

AUTO

TIME

MANUAL

IF REMOTE STOP

CONTROL IS USED,

FROM TERM. 25 TO 35.

843

120 VAC

LIQUID LINE SOLENOID

AGZ REMOTE EVAP ONLY

BELL

FIELD WIRING

FACTORY WIRING

3 PHASE

POWER SUPPLY

DISCONNECT

(BY OTHERS)

TERMINAL

BLOCK

GND LUG

TO COMPRESSOR(S)

AND FAN MOTORS

NOTE: ALL FIELD WIRING TO BE INSTALLED AS NEC CLASS 1 WIRING SYSTEM WITH CONDUCTOR RATED 600 VOLTS

120VAC

CONTROL POWER

SEPARATE EVAP.

HEATER POWER

FIELD WIRED

ALARM

(BY OTHERS)

FIELD WIRED

BELL

OPTION

DISCONNECT (BY OTHERS)

DISCONNECT

120VAC

(BY OTHERS)

120 VAC 1.0 AMP MAX

HOT GAS BYPASS SOLENOID

120 VAC 1.0 AMP MAX

(BY OTHERS)

120 VAC 1.0 AMP MAX

FUSED CONTROL

CIRCUIT

TRANSFORMER

10A

FUSE

(BY OTHERS)

10A

FUSE

(BY OTHERS)

SV1

SV5

FUSE

HEATER POWER OPTION

IS USED - REMOVE

MECHANICAL JUMPER

& TB1-15 AND TB1-16.

CLOCK OFF

REMOTE STOP

SWITCH

(BY OTHERS)

SWITCH

(BY OTHERS)

CHW FLOW SWITCH

---MANDATORY–(BY OTHERS)

CHW RESET

(BY OTHERS)

NOR. OPEN PUMP AUX. CONTACTS (OPTIONAL)

OFF

REMOVE LEAD 843

RELAY

1 2

24VAC

Note: See control and power wiring diagrams on unit control panel for specific unit information.

IOMM AGZB1 AGZ 010B through 034B 27

Dimensions & Weights

CERTIFIED, 2 FAN, AGZ-B

QTY. 4

3.00

R331987101

AGZ029-034 = 59

3.00

Figure 8, AGZ 010BS - 017BS, Packaged (See page 30 for additional dimensions and weights)

ACCESS

PANEL

QTY.2

EVAP. INLET

31.70

EVAP. OUTLET

14.66

73.80

46.18

49.06

5.17

L1, L2L3, L4

21.18

11.27

2.61

.875

POWER ENTRY

KNOCKOUT

(OTHER SIDE)

CONTROL ELECTRICAL KNOCKOUT

40.18

24.57

4.00 MOUNTING HOLES DIA. 1.00 INCH

.875

ACCESS DOORS

CONTROL BOX

31.15

MOUNTING

HOLES

46.42

ACCESS

DOOR

7.64

POWER ENTRY

R331987001

51.00

Figure 9, AGZ 020BS - 034BS,packeged (See page 30 for additional dimensions and weights)

QTY.2

EVAP.

ACCESS

PANEL

EVAP. OUTLET

14.66

49.06 49.06

106.23

INLET

11.27

84.95

31.70

DIM. A = AGZ020-025 = 24.6"

AGZ029-034 = 33.0"

DIM. B = AGZ020-025 = 40.2"

AGZ029-034 = 48.7"

.875

POWER ENTRY

KNOCKOUT (OTHER SIDE)

5.17

2.67 A

L1, L2L3, L4

21.18

.875

CONTROL

ELECTRICAL

KNOCKOUT

NOTE:

L2 & L4 ARE LOCATED ON1. OPPOSITE SIDE OF UNIT.

ALL WEIGHTS ARE IN POUNDS.2.

CONTROL PANEL

ACCESS DOORS

ACCESS

DOOR

31.10

MOUNTING

HOLES

46.38

7.64

CERTIFIED, 3 FAN, AGZ-B

POWER ENTRY

AGZ020-025 =51

28 AGZ 010B through 034B IOMM AGZB1

Figure 10, AGZ 010 - 017BM Remote Evap. (See page 30 for additional dimensions and weights

CERTIFIED, 2 FAN, AGZ-B REMOTE

DIM. A = ACZ025-028 = 24.6"

NOTE:

ACZ033-039 = 59

ACCESS

PANEL

NOTE:

L2 & L4 ARE LOCATED ON1. OPPOSITE SIDE OF UNIT.

ALL WEIGHTS ARE IN POUNDS.2.

5.17

HOT GAS BYPASS

L1, L2L3, L4

73.80

21.18 X

46.18

49.06

18.84

9.19

4.56

5.06

8.86

.875

POWER ENTRY

KNOCKOUT

(OTHER SIDE)

CONTROL

ELECTRICAL

20.79

KNOCKOUT

24.57

SUCTION

LIQUID

4.00 MOUNTING HOLES DIA. 1.00 INCH

.875

CONTROL BOX

ACCESS DOORS

ACCESS

DOOR

R331987401

31.15

MOUNTING

HOLES

46.42

POWER ENTRY

51.00

7.64

Figure 11, AGZ 020BM - 034BM (See page 30 for additional dimensions and weights

ACCESS

PANEL

DIM. B = ACZ025-028 = 40.2"

DIM. C = ACZ025-033 = 18.8"

DIM. D = ACZ025-033 = 4.5"

ACZ033-039 = 33.0"

ACZ033-039 = 48.7"

ACZ039 = 12.6"

ACZ039 = 7.5"

L2 & L4 ARE LOCATED ON1. OPPOSITE SIDE OF UNIT.

ALL WEIGHTS ARE IN POUNDS.2.

49.06 49.06

106.23

.875 POWER ENTRY KNOCKOUT (OTHER SIDE)

84.95

5.17 HOT GAS BYPASS

.875

CONTROL

ELECTRICAL

KNOCKOUT

2.67 SUCTION

9.19

L1,L2L3,L4

21.18

LIQUID

5.06

8.86

20.79

R331987501 CERTIFIED, 3 FAN, AGZ-B REMOTE

CONTROL PANEL

ACCESS DOORS

ACCESS

DOOR

31.10

MOUNTING

HOLES

46.38

POWER ENTRY

ACZ025-028 =51

7.64

IOMM AGZB1 AGZ 010B through 034B 29

Remote Evaporators

3.5

(90)

1.2

(30)

Inlet

Outlet

Suction

Temp Sensor

Figure 12, Remote Evaporators, for AGZ 010BM – 034BM

30.2

(767)

Liquid

.35 (9)

8.2 (208)

10.2 (260)

1.2

(30)

3.5

(90)

AGZ

Model

010

013

017

020

025

029

034

Liquid Line Conn.

Brazed, in (L).

1.125 2.125 0.75 2.0 3.6 (91)

1.125 2.125 0.75 2.0 6.0 (153)

1.125 2.125 0.75 2.0 7.1 (181)

1.125 2.125 0.75 2.0 7.7 (195)

1.125 2.125 0.75 2.0 10.6 (271)

1.375 2.125 0.75 2.0 13,8 (351)

1.375 2.125 0.75 2.0 19.0 (483)

Suction Line Conn.

Brazed, in (S).

Temp. Sensor

NPT, in. (TS)

Victaulic

Water Conn.

In. (W)

Dimension

“A”

in. (mm)

30 AGZ 010B through 034B IOMM AGZB1

ACZ/AGZ Dimensions and Weights

010B

(IN.)

(LBS)

BYPASS

010B

MOUNTING CORNER WEIGHTS (LBS.)

EVAP

010B

Table 14, Packaged Chiller, Dimensions and Weights

AGZ UNIT SIZE

013B 017B 020B 025B 029B 034B

CENTER OF GRAVITY

(IN.)

X Y Z

28.00 21.50 23.40 1085 1095 398 392 149 147 2 279 275 267 263

27.40 21.40 23.90 1170 1190 452 426 150 141 2 315 297 288 271

27.50 21.60 24.00 1280 1300 493 463 167 157 2 344 323 316 297

38.50 21.80 23.90 1505 1525 564 534 209 198 2 502 475 271 257

39.50 19.40 24.00 1610 1635 593 554 239 224 2 531 496 301 282

41.00 22.75 24.20 1800 1830 645 595 291 269 2 583 238 353 326

35.60 23.70 23.50 2270 2315 890 869 259 253 2 779 761 369 361

SHIP WT.

(LBS)

OPN. WT.

(LBS)

Table 15, Remote Evaporator, Dimensions and Weights

AGZ

REMOTE

EVAP.

013B 017B 020B 025B 029B 034B

CENTER OF GRAVITY

X Y Z

27.50 21.70 22.90 1000 1015 369 379 124 128 1.125 0.875 0.625

26.50 21.60 23.40 1065 1090 421 416 115 113 1.625 0.875 0.625

26.60 21.80 23.30 1150 1190 454 449 124 123 1.625 0.875 0.625

38.50 21.90 23.30 1370 1420 501 498 186 185 1.625 0.875 0.625

38.50 19.10 23.30 1390 1445 508 505 189 188 1.625 0.875 0.625

41.00 23.00 23.30 1565 1625 540 538 244 243 1.625 0.875 0.875

34.60 24.00 22.40 1975 2050 753 807 201 215 2.125 0.875 0.875

SHIP

WT.

(LBS)

OPN.

(LBS)

LIFTING CORNER WEIGHTS

WT.

LIFTING CORNER

WEIGHTS (LBS)

L1 L2 L3 L4

L1 L2 L3 L4 SUCTION LIQUID

EVAP.

CONN.

(IN.)

VICTAULIC

CONNECTION SIZES (IN. O.D.)

MOUNTING CORNER

WEIGHTS (LBS.)

M1 M2 M3 M4

HOT GAS

Table 16, Mounting Weights

AGZ

REMOTE

013B 017B 020B 025B 029B 034B

M1 M2 M3 M4

257 264 236 243 290 286 246 243 312 309 266 263 446 443 241 240 453 449 245 243 488 487 296 295 656 703 297 318

IOMM AGZB1 AGZ 010B through 034B 31

System Maintenance

General

On initial start-up and periodically during operation, it will be necessary to perform certain routine service checks. Among these are taking electric leg readings. Some readings are readily available on the MicroTech II controller’s display.

Lubrication

No routine lubrication is required on the AGZ units. The fan motor bearings are of the permanently lubricated type and require no lubrication.

Electrical Terminals

Electric shock hazard. Disconnect and tag out all sources of power to the unit before continuing with following service or severe personal injury or death can result.

Normal heating and cooling of the wire will cause terminals to loosen. Retighten all power electrical terminals every six months.

Condensers

Condensers are air-cooled and constructed with 3/8” (9.5mm) O.D. internally finned copper tubes bonded in a staggered pattern into slit aluminum fins. No maintenance is ordinarily required except the occasional removal of dirt and debris from the outside surface of the fins. Use locally purchased foaming condenser coil cleaners for periodic cleaning of the coil. Condenser cleaners may contain harmful chemicals, be careful when using cleaners. Care should be taken not to damage the fins during cleaning. All chemical cleaners should be thoroughly rinsed from the coils.

WARNING

Refrigerant Sight glass

Observe the refrigerant sight glass monthly. A clear glass of liquid indicates adequate subcooled refrigerant charge in the system to ensure proper feed through the expansion valve. Bubbling refrigerant in the sight glass indicates the system is short of refrigerant charge. Sub-cooling should be verified to prevent overcharging. Refrigerant gas flashing in the sight glass could also indicate an excessive pressure drop in the line, possibly due to a clogged filter-drier or a restriction elsewhere in the system. The sight glass indicates what moisture condition corresponds to a given element color. If the sight glass does not indicate a dry condition after about 12 hours of operation, the refrigerant or oil should be tested for moisture.

32 AGZ 010B through 034B IOMM AGZB1

Standard MicroTech II Controller

Table of Contents

Overview .............................................................................34

General Description ............................................................. 34

Compressor Motor Description .......................................34

FanTrol Head Pressure Control .......................................34

Inputs/Outputs ................................................................ 35

Setpoints ........................................................................35

Equipment Protection Alarms ......................................... 37

Control Functions and Definitions ..................................39

Limit Alarms ..................................................................39

Control Functions ...........................................................39

Unit Enable ....................................................................41

Unit Mode Selection .......................................................41

Unit State ....................................................................... 42

Evaporator Pump state ....................................................43

Condenser Fans ..............................................................44

Compressor Control........................................................ 45

Using the Controller............................................................. 39

Display and Keyboard ..................................................... 48

Getting Started .....................................................................48

Menu Screens ................................................................. 49

Menu Matrix...................................................................51

View Screens Defined ..................................................... 52

Alarm Screens Defined ...................................................54

Set Screens Defined........................................................55

Software Version AGZSU0102D

IOMM AGZB1 AGZ 010B through 034B 33

Overview

The MicroTech II controller’s state-of-the-art design will not only permit the chiller to run more efficiently, but will also simplify troubleshooting if a system failure occurs. Every MicroTech II controller is programmed and tested prior to shipment to contribute to a trouble-free start-up.

Release Version

This manual covers Software Release AGZ SU0102D

Operator-friendly

The MicroTech II controller’s menu structure is separated into three distinct categories, which provide the operator or service technician with a full description of current unit status, control parameters, and alarms. Security protection prevents unauthorized changing of the setpoints and control parameters.

The MicroTech II controller continuously performs self-diagnostic checks, monitoring system temperatures, pressures and protection devices, and will automatically shut down a compressor or the entire unit should a fault occur. The cause of the shutdown will be retained in memory and can be easily displayed in plain English for operator review. The MicroTech II chiller controller will also retain and display the time the fault occurred. In addition to displaying alarm diagnostics, the MicroTech II chiller controller also provides the operator with a warning of limit (pre-alarm) conditions.

Staging

The two scroll compressors are staged on and off as a function of leaving chilled water temperature. Lead/lag is automatic and switched every ten starts.

General Description

Compressor Motor Protection

The solid-state compressor motor protector module incorporates a 2-minute “time-off” relay utilizing the bleed-down capacitor principle. Any time the protection system opens or power to the module is interrupted, the 2-minute “time-off” delay is triggered and the module will not reset for two minutes. Once the 2-minute period has passed the motor protector contacts M1 and M2 reset, provided the protection system is satisfied and power is applied to the module.

Note: If the power circuit is broken once the 2-minute period is passed, the pilot circuit will reset without delay when power is reapplied.

AGZ 010: The model AGZ 010 compressor has internal line breakage with automatic reset.

FanTrol Head Pressure Control

FanTrol is the standard method of head pressure control that automatically cycles the condenser fan motors in response to condenser pressure. This function is controlled by the microprocessor, maintains head pressure and allows the unit to run at low ambient air temperatures down to 35°F (1.7°C). Fans are staged as follows:

Table 17, Fan Staging Pressures

Fan Two-Fan Unit Three-Fan Unit

Stage #1 On 150 psig, Off with unit On 150 psig, Off with unit Stage #2 On 290 psig, Off 170 psig On 290 psig, Off 170 psig Stage #3 -- On 310 psig, Off 180 psig

Note: Fan #1 is on with first compressor above 75°F (24°C).

34 AGZ 010B through 034B IOMM AGZB1

Inputs/Outputs

Table 18, Inputs and Outputs

Analog Inputs

# Description Signal Source Range

1 Reset of Leaving Water Temperature 4-20 mA Current

2 Evaporator Refrigerant Pressure 0.5 to 4.5 VDC (NOTE 1) 3 Condenser Refrigerant Pressure 0.5 to 4.5 VDC (NOTE 1) 4 Leaving Evaporator Water Temperature 5 Outside Ambient Temperature

Thermister (10k at 77°F, 25°C) Thermister (10k at 77°F, 25°C)

NOTE 1: Value at the converter board input. Value at the converter board output is 0.1 VDC – 0.9 VDC.

Analog Outputs

# Description Output Signal Range

1-4 None -- --

Digital Inputs

# Description Signal Signal

1 Unit OFF Switch 0 VAC (Stop) 24 VAC (Auto) 2 Remote Start/Stop 0 VAC (Stop) 24 VAC (Start) 3 Evaporator Water Flow Switch 0 VAC (No Flow) 24 VAC (Flow) 4 Motor Protection 0 VAC (Fault) 24 VAC (No Fault) 5 Ice Mode Switch 0 VAC (Normal) 24 VAC (Ice) 6 Phase Voltage Fault 0 VAC (Fault) 24 VAC (No Fault) 7 Open -- -8 Open -- --

0 to10 degrees 60°F max inlet 0 to 132 psi

3.6 to 410 psi

-58 to 212°F

Digital Outputs

# Description Load Output OFF Output ON

1 Alarm Alarm Indicator Alarm OFF Alarm ON 2 Evaporator Water Pump Pump Contactor Pump OFF Pump ON 3 Liquid Line Solenoid Cooling OFF Cooling ON 4 Motor Control Relay #1 Starter Compressor OFF Compressor ON 5 Motor Control Relay #2 Starter Compressor OFF Compressor ON 6 Condenser Fan #1 Fan Contactor Fan OFF Fan ON 7 Condenser Fan #2 Fan Contactor Fan OFF Fan ON 8 Condenser Fan #3 Fan Contactor Fan OFF Fan ON

Setpoints

The setpoints shown in Table 19 are battery-backed and remembered during power off, are factory set to the Default value, and can be adjusted within the value shown in the Range column.

The PW (password) column indicates the password level that must be entered in order to change the setpoint. Passwords are as follows:

O = Operator [0100]

M = Manager, [2001] M level settings are not normally changed for chilled water airconditioning applications.

IOMM AGZB1 AGZ 010B through 034B 35

Table 19, Setpoints

Description Default Range PW

Unit

Unit Enable OFF OFF, ON O

Unit Mode COOL

Control Source SWITCHES

Available Modes COOL

Display Units Language ENGLISH ENGLISH, O Cool LWT Ice LWT Evap Delta T Startup Delta T Stop Delta T 0.5F 0 to 3.0F O Max Pulldown Rate 1.0F * Refrigerant Type (Note 1) None R22, R407c -BAS Protocol Modbus BACnet, LONW Ident Number 001 001 to 999 M Baud rate 9600 1200,2400,4800,9600,19200 M * SpeedTrol Option N N,Y M Password 0000 0000 to 9999 --

Staging

Stage Up Delay 120 20 to 240 sec M Stage Down Delay 30 10 to 60 sec M

Timers

Evap Flow Proof 3 sec 1 to 10 sec M Evap Recirculate Timer 30 sec 15 to 300 sec. M Low Evap Pressure Delay 30 sec 15 sec to 30sec M Ice Time Delay 12 hrs. 1 to 23 hrs M Clear Ice Delay NO No, Yes M Start-Start 15 min 10 to 60 min M Stop-Start 5 min 3 to 20 min M Stage Up Delay 240 sec. 20 to 480 sec. M Stage Down Delay 30 sec. 10 to 60 sec. M Comp 1 Enable On Off, On Comp 2 Enable On Off, On

Alarms

Evaporator Freeze Low Evap Pressure 58 psi 30 to 60 psi M Low Evap Pressure-Hold 59 psi 31 to 65 psi M Low Evap Pressure-Unload 59 psi 31 to 65 psi M High Condenser Stage Down 370 psi 365 to 375 psi M High Condenser Pressure 380 psi 380 to 390 psi M * Phase Voltage Protection N N,Y M * Low Ambient Lockout

Condenser Fans

Fan Stages 2 2-3 Speedtrol Option No No,Yes Stage #1 On (OAT<75°F) Stage #2 On 290 psi 230 to 330 psi M Stage #3 On 300 psi 230 to 330 psi M Stage #1 Off 140 psi 130 to 170 M

Continued next page.

COOL COOL w/Glycol ICE w/Glycol TEST SWITCHES, KEYPAD, NETWORK COOL COOL w/GLYCOL COOL/ICE w/GLYCOL TEST

°F/psi °F/psi

44. 0°F 20.0 to 60.0 °F

40. 0°F 20.0 to 40.0 °F

10. 0°F 6.0 to 16.0 °F

10.0°F 1.0 to 15.0 °F

0.5 to 5.0°F

ORKS

, Modbus M

36.0 °F 18 to 42 °F

35.0 °F –2 to 60 °F

200psi 140 to 200 psi M

O O O O

36 AGZ 010B through 034B IOMM AGZB1

Description Default Range PW

Stage #2 Off 180 psi 150 to 200 psi M Stage #3 Off 190 psi 150 to 200 psi M

Sensor Offsets

Evaporator Refrig Press Sensor Offset 00.0 psi -20.0 to 20.0 psi

Condenser Refrig Press Sensor Offset 00.0 psi -20.0 to 20.0 psi

Leaving Evaporator Water Temp Sensor

Outside Ambient Temperature Sensor

NOTES:

1. This setting is a one-time only setting and is mad in the factory.

2. (*) These items are factory set prior to shipment.

0.0 °F -5.0 to 5.0 °F

Automatic Adjusted Ranges

The following are setpoints that will be limited based on the option(s) selected.

Evaporator Leaving Water Temperature

Mode Range

Unit Mode = Cool

Unit Mode = Cool w/Glycol

Evaporator Freeze Temperature

Mode Range

Unit Mode = Cool Unit Mode = Cool w/Glycol, Ice w/Glycol

40 to 60°F

20 to 60°F

36 to 42°F

18 to 42°F

Low Ambient Lockout Temperature

SpeedTrol Range

SpeedTrol = N SpeedTrol = Y

35 – 60°F

-2 – 60°F

Low Evaporator Pressure Hold and Unload

Mode Refrigerant Range

Unit Mode = Cool R22 55 to 65 Psig Unit Mode = Cool w/Glycol, Ice w/Glycol R22 24 to 65 Psig Unit Mode = Cool R407c 58 to 65 Psig Unit Mode = Cool w/Glycol, Ice w/Glycol R407c 20 to 65 Psig

Dynamic Default Values

Some setpoints will have different default values loaded depending on the value of other setpoints.

Low Evaporator Pressure Hold

Refrigerant Default Value

R22 59 psi

R407C 60 psi

Low Evaporator Pressure Unload

Refrigerant Default Value

R22 58 psi

R407C 59 psi

IOMM AGZB1 AGZ 010B through 034B 37

Setpoint Security

All setpoints are protected by using passwords. Two four-digit passwords provide OPERATOR and/or MANAGER levels of access to changeable parameters. Once a password has been entered, it remains valid for 15 minutes after the last key-press on the unit controller.

After a valid password has been entered, setpoints may be changed. If the operator attempts to edit a setpoint on a controller while the correct password is not active, no action will be taken.

Passwords can be entered using the ENTER PASSWORD screen which is the last screen in the SET UNIT SPs column.

The password is entered by pressing the ENTER key, scrolling to the correct value with the UP and DOWN arrow keys, and pressing ENTER again. The entered password is not shown after the enter key is pressed. Once the correct password has been entered, the PASSWORD screen indicates which password is active (operator or manager). If the wrong password is entered, there is no level of access so the active password displays “none”. Entering an incorrect password while a password is active will render that password inactive.

Equipment Protection Alarms

Equipment protection alarms execute rapid compressor shutdown (no pumpdown cycle), triggers the alarm output, lights the red alarm light on the controller left arrow button and registers it in the alarm log.

The following table identifies each equipment protection alarm, gives the condition that causes the alarm to occur, and states the action taken because of the alarm. Otherwise, the alarm is manually reset, requiring the operator to clear the alarm.

Table 20, Shutdown Alarms

Description Occurs When:

No Evaporator Water Flow (See NOTE)

Low Evaporator Pressure

High Condenser Pressure

Mechanical High Pressure MHP input is low Rapid Stop Manual

Motor Protection

Phase Voltage Protection (opt)

Low Ambient Restart Fault

Evaporator Freeze Protect Evap LWT < Evaporator Freeze SP Rapid Stop Manual Leaving Evaporator Water Temperature Sensor Fault Evaporator Pressure Sensor Fault Condenser Pressure Sensor Fault Outside Ambient Temperature Sensor Fault

Evap Pump State = RUN and Flow Switch Digital Input = No Flow and time greater than Evap Flow Proof SP Evaporator Press < Low Evap Pressure SP start Low Evap Pressure Time Delay – if after Time Delay if Evap Press > SP continue else stop Condenser Press > High Condenser Pressure SP

Digital Input = High Motor Temperature On Power Up – Delay 150 Sec. before checking

If Phase Voltage Protection = Y, Then Digital Input = Phase/Voltage Problem

Failed three consecutive low ambient start attempts

Sensor shorted or open Rapid Stop Manual

Sensor is open or shorted Rapid Stop Manual

NOTE: Beginning with this software version, two automatic resets per day (beginning at 12:00 am) are allowed on the flow loss alarm. The Unit State remains on Auto and the evaporator will go back to Start, waiting for flow.

Action

Taken

Rapid Stop Auto/Manual

Rapid Stop Manual

Rapid Stop

Rapid Stop Manual

Reset

Phase/Voltage

Input Returns

to Normal

38 AGZ 010B through 034B IOMM AGZB1

Events (Limit Alarms)

The following events limit the operation of the chiller in some way as described in the Action Taken column. These alarms are auto-clearing based on reaching the conditions in the reset column.

Table 21, Events (Limit Alarms)

Description Occurs When: Action Taken Reset

Condenser Pressure High Unload

Failed Pumpdown

Low Evaporator Pressure – Hold Low Evaporator Pressure – Unload

NOTE: SP = Setpoint

Pressure > High Condenser Stage Down setpoint Unit is pumping down for over 60 seconds Pressure < Low Evap Pressure–Hold setpoint Pressure < Low Evap Pressure– Unload setpoint

Control Functions and Definitions

Control Band

Control Band = Evap delta setpoint * 0.6

Upper and Lower Control Band

The control band is normally centered around the active LWT setpoint. If the chiller is not set up to use glycol, then the control band will be shifted up relative to the LWT setpoint to keep the lower end of the control band at least at 39°F. If the band doesn’t need to be shifted to achieve this, it will remain centered on the active LWT setpoint.

Shutoff Stage #2

Shut down unit N/A

Hold @ Stage 1 Shutoff Stage 2

Condenser Press drops below (SP – 100psi)

Evap Press rises above (SP + 8psi) Evap Press rises above (SP + 10 psi)

In the staging logic, an upper and lower control band are used. The lower control band is calculated as follows:

IF Active LWT Setpoint – 39 < 0.5 * Control Band THEN

Lower Control Band = Active LWT Setpoint – 39

ELSE Lower Control Band = 0.5 * Control Band

The upper control band is then Control Band – Lower Control Band

Leaving Water Reset

The leaving water reset input uses a 4-20mA signal to reset the leaving water setpoint to a higher value. The adjustment varies linearly from 0 to 10°F, with a reset of 0 for a 4mA signal and a reset of 10 for a 20mA signal.

Active LWT Setpoint

The active LWT setpoint represents the current control setpoint based on unit mode and reset. If unit mode is ice, then the active setpoint is equal to the ice setpoint. If the unit mode is cool, the active setpoint is the cool setpoint plus the leaving water reset value.

LWT Error

LWT error compares the actual LWT to the active LWT setpoint. The equation is:

LWT error = LWT – active LWT setpoint

LWT Slope

LWT slope is calculated such that the slope represents a time frame of one minute.

IOMM AGZB1 AGZ 010B through 034B 39

Every 12 seconds, the current LWT is subtracted from the value 12 seconds back. This value is added to a buffer containing values calculated at the last five intervals. The final result is a slope value that is an average over the past 60 seconds.

Pulldown Rate

The slope value calculated above will be a negative value as the water temperature is dropping. For use in some control functions, the negative slope is converted to a positive value by multiplying by –1.

Refrigerant Saturated Temperature

Methods for calculating saturated refrigerant temperature differ with each refrigerant.

R22 Saturated Temperature

Evaporator saturated temperature and condenser saturated temperature are calculated from the pressures for each circuit. The pressure will be fitted to a curve made up of 13 straight line segments. The points used to define these segments are as follows.

Pressure (PSI) Temperature (oF)

24.0 0

34.7 12.0

47.6 24.0

62.8 36.0

80.8 48.0

101.6 60.0

126.2 72.0

153.8 84.0

185.2 96.0

220.6 108.0

260.5 120.0

305.2 132.0

355.1 144.0

430.4 160.0

R407C Saturated Temperature

Evaporator dew point and condenser midpoint are calculated using 32-bit math. The equation is as follows:

If Pressure < 120 psi Then

Saturation = [Pressure x 145/105] – [(Pressure2)/2000] – 250

If Pressure >= 120 psi Then

Saturation = [Pressure x 46/94] – [Pressure2/25000] + 145

Evaporator Approach

The evaporator approach is calculated for each circuit. The equation is as follows:

Evaporator Approach = LWT – Evaporator Saturated Temperature

Suction Superheat

Suction superheat is calculated for each circuit using the following equation:

Suction superheat = Suction Temperature – Evaporator Saturated Temperature

40 AGZ 010B through 034B IOMM AGZB1

Pumpdown Pressure

The pressure to which a circuit will pumpdown is based on the Low Evaporator Pressure Unload setpoint. The equation is as follows:

Pumpdown pressure = Low evap pressure unload – 15 psi , with the calculated value limited to a minimum of 10 psi.

Unit Enable

Enabling and disabling the chiller is controlled by the Unit Enable Setpoint with options of OFF and ON. This setpoint can be altered by the Unit OFF input, Remote input, keypad entry, and BAS request. The Control Source Setpoint determines which sources can change the Unit Enable Setpoint with options of SWITCHES, KEYPAD or NETWORK.

Changing the Unit Enable Setpoint can be accomplished according to the following table. NOTE: An “x” indicates that the value is ignored.

Unit Off

Input

OFF x x x x OFF

x SWITCHES OFF x x OFF ON SWITCHES ON x x ON ON KEYPAD x OFF x OFF ON KEYPAD x ON x ON ON NETWORK x x OFF OFF ON NETWORK OFF x x OFF ON NETWORK ON x ON ON

Unit Mode

The overall operating mode of the chiller is set by the Unit Mode Setpoint with options of COOL, COOL w/Glycol, ICE w/Glycol, and TEST. This setpoint can be altered by the keypad, BAS, and Mode input. Changes to the Unit Mode Setpoint are controlled by two additional setpoints.

• Available Modes Setpoint: Determines the operational modes available at any time

with options of COOL, COOL w/Glycol, COOL/ICE w/Glycol, ICE w/Glycol and

TEST.

• Control Source Setpoint: Determines the source that can change the Unit Mode

Setpoint with options of KEYPAD, NETWORK, or SWITCHES.

When the Control source is set to KEYPAD, the Unit Mode stays at its previous setting until changed by the operator. When the Control source is set to BAS, the most recent BAS mode request goes into effect even if it changed while the Control source was set to KEYPAD or DIGITAL INPUTS.

Changing the Unit Mode Setpoint can be accomplished according to the following table. NOTE: An “x” indicates that the value is ignored.

Control Source

Setpoint

Remote

Input

Key-

Pad Entry

BAS

Request

Unit

Enable

Control Source

Setpoint

x x x x

x x x x COOL w/Glycol COOL w/Glycol SWITCHES OFF x x COOL/ICE w/Glycol COOL w/Glycol SWITCHES ON x x COOL/ICE w/Glycol ICE w/Glycol

KEYPAD x COOL w/Glycol x COOL/ICE w/Glycol COOL w/Glycol

KEYPAD x ICE w/Glycol x COOL/ICE w/Glycol ICE w/Glycol NETWORK x x COOL COOL/ICE w/Glycol COOL w/Glycol NETWORK x x ICE COOL/ICE w/Glycol ICE w/Glycol

x x x x ICE w/Glycol ICE w/Glycol x x x x TEST TEST

IOMM AGZB1 AGZ 010B through 034B 41

Mode Input

Keypad Entry

BAS

Request

Available Modes

Setpoint

COOL

Unit Mode

COOL

Unit Test Mode

The unit test mode allows manual testing of controller outputs. Entering this mode requires the following conditions.

• Unit Switch = OFF

• Manager password active.

• Available Unit Mode setpoint = TEST

A test menu can then be selected to allow activation of the outputs. It is possible to switch each digital output ON or OFF and set the analog outputs to any value.

Power Up Start Delay

After powering up the unit, the motor protectors may seem to not work properly for up to 150 seconds. After the control is powered up, no compressor can start for 150 seconds. In addition, the motor protect inputs are ignored during this time so as to avoid tripping a false alarm.

Ice Mode Start Delay

An adjustable start to start ice delay timer will limit the frequency with which the chiller may start in Ice mode. The timer starts when the first compressor starts while the unit is in ice mode. While this timer is active, the chiller cannot restart in Ice mode. The time delay is user adjustable.

The ice delay timer may be manually cleared to force a restart in ice mode. A setpoint specifically for clearing the ice mode delay is available. In addition, cycling the power to the controller will clear the ice delay timer.

Unit State

The Unit shall always be in one of three states. These states are Off, Auto, and Pumpdown. Transitions between these states are shown in the following diagram (Figure 13, Unit State Diagram).

T1: Off to Auto

All of the following must be true:

• Unit Enabled

• No Alarm

• IF Unit Mode = Ice THEN [Ice Timer Expired]

T2: Auto to Pumpdown

Any of the following must be true:

• Keypad Enable = Off

• BAS Enable = Off

• Remote Switch = Off

• Pumpdown Alarm Active

T3: Pumpdown to Off

Any of the following must be true:

• Unit Alarm

• Unit Switch Off

• No Compressors Running

T4: Auto to Off

Any of the following must be true:

• Unit Alarm

• Unit Switch Off

• No Compressors Running AND [Unit Mode = Ice AND Ice Delay Active]

42 AGZ 010B through 034B IOMM AGZB1

Figure 13, Unit State Diagram

Unit State Diagram

Power On

Pumpdown Auto

Off

Evaporator Water Pump State Control

Operation of the evaporator pump is controlled by the state-transition diagram shown below.

Figure 14, Evaporator Pump State

Evaporator Pump

Power ON

RUN

See transition code on following page.

States

OFF

START

IOMM AGZB1 AGZ 010B through 034B 43

Transitions:

T1 – Transition from Off to Start Requires any of the following

• Unit state = Auto

• LWT < Freeze setpoint - 1

T2 – Transition from Start to Run

• Flow ok for time > evaporator recirculate time

T3 – Transition from Run to Off

• Unit state = Off AND LWT > Freeze setpoint

T4 – Transition from Start to Off

• Unit state = Off AND LWT > Freeze setpoint

T5 – Transition from Run to Start Requires all of the following

• Evaporator water flow loss for time > evaporator flow proof setpoint

Condenser Fans

Condenser fans are staged up and down based on the fan stage setpoint. These setpoints define pressures at which fans will start or stop.

Fan 1 will start with the first compressor when the ambient temperature is greater than 75°F. Below 75°F, this fan starts when the condenser pressure gets up to the Stage #1 On setpoint. Fan 2 will start when the condenser pressure gets up to the Stage #2 On setpoint, and fan 3 will start when the condenser pressure gets up to the Stage #3 On setpoint.

Fan 3 will stop when the condenser pressure drops to the Stage #3 Off setpoint, and Fan 2 will stop when the condenser pressure drops to the Stage #2 Off setpoint. Fan 1 will stop when the pressure drops down to the Stage #1 Off setpoint.

Low OAT Start

In order to avoid low pressure alarms at startup, low OAT start logic allows for running at low pressures for a longer time than normal as well as multiple start attempts.

A low OAT start is initiated if the condenser saturated temperature is less than 85°F when the compressor starts. Once this happens, the circuit is in this low OAT start state for a time equal to the low OAT start timer setpoint. During this time, the freezestat logic and the low pressure events are disabled. The absolute limit of 5 psi is still enforced.

At the end of the low OAT start, the evaporator pressure is checked. If the pressure is greater than, or equal to, the low evaporator pressure unload setpoint, the start is considered successful. If the pressure is less than the unload setpoint, the start is not successful and the compressor will stop. Three start attempts are allowed before tripping on the restart alarm. So if on the third attempt, the start is not successful, the restart alarm is triggered.

The restart counter is be reset when either a start is successful or the circuit is off on an alarm.

Circuit Capacity Overrides

The following conditions override the automatic capacity control when the chiller is in Cool Mode only. These overrides keep the unit from entering a condition in which it is not designed to run.

Low Evaporator Pressure

If the evaporator pressure drops below the Low Evaporator Pressure Hold setpoint, the Low Evaporator Pressure Inhibit event is triggered. This can occur with either one or two compressors running. When triggered, the second compressor will not be allowed to start if only one is currently running. If both compressors are already running, no action is taken.

44 AGZ 010B through 034B IOMM AGZB1

If the evaporator pressure drops below the Low Evaporator Pressure Unload setpoint, the Low Evaporator Pressure Unload event is triggered. This can only occur when both compressors are running. When triggered, one compressor is shut off.

These events are logged to an event log when they occur. Both remain active until the evaporator pressure rises 5 psi above the hold setpoint or both compressors are off.

High Condenser Pressure

If the discharge pressure rises above the High Condenser Pressure Unload setpoint and both compressors are running, the High Condenser Pressure Unload event is triggered. One compressor will be shut off when this occurs.

This event will also be logged to an event log when it occurs. It will remain active until the condenser pressure drops 100 psi below the unload setpoint. While active, the second compressor cannot turn back on.

Maximum LWT Rate

The maximum rate at which the leaving water temperature can drop is limited by the Maximum Pulldown Rate setpoint when the unit mode is Cool. If the rate exceeds this setpoint, no more compressors can be started until the Pulldown Rate is less than the setpoint. Running compressors will not be stopped as a result of exceeding the maximum pulldown rate.

Low Ambient Lockout

If the OAT drops below the low ambient lockout setpoint, then the unit will do a normal stop. Once the lockout has been triggered, no compressors will start until the OAT rises to the lockout setpoint plus 5°F.

Compressor Control

Compressor Available

A compressor is available to start when the following are true:

• Unit state = auto

• Evap state = run

• Low OAT lockout is not active

• Power up start delay is expired

• No limit events active

• No cycle timers active for the compressor

• Compressor enable setpoint = On

Compressor Start/Stop Timing

This section determines when to start or stop a compressor. There are two separate functions used, one for staging up and one for staging down.

Stage Up Now

The Stage Up Now flag is set based on the following tests:

If Unit mode = Cool, AND no compressors are running, AND LWT error > Start delta + Upper Control Band, AND Motor Protect Timer is expired, AND Stage up timer is expired, THEN

Stage Up Now = True

IOMM AGZB1 AGZ 010B through 034B 45

ALSO

If Unit Mode = Cool, AND At least one compressor is running, AND LWT error > Upper Control Band, AND Pulldown rate <= Max pulldown rate, AND Compressors running < unit capacity limit, AND Stage up timer is expired, THEN

Stage Up Now = True

ALSO

If Unit Mode = Ice, AND no compressors are running, AND LWT error > Start delta + Upper Control Band, AND Motor Protect Timer is expired, AND Ice Delay Timer is expired, AND Stage up timer is expired, THEN

Stage Up Now = True

ALSO

If Unit Mode = Ice, AND LWT error > 0, AND At least one compressor running, THEN

Stage Up Now = True

Stage Down Now

The Stage Down Now flag is set based on the following tests:

If Unit Mode = Cool, AND LWT error < -(Lower Control band), AND More than one compressor is running, AND Stage down timer is expired, THEN

Stage Down Now = True

ALSO

If Unit Mode = Cool, AND LWT error < -(Lower Control band) - stop delta, AND One compressor is running, AND Stage down timer is expired THEN

Stage Down Now = True

ALSO

If Unit Mode = Cool, AND Number of compressors running > Demand limit, AND Stage down timer expired, THEN

Stage Down Now = True

ALSO

If Unit Mode = Ice, AND LWT error < 0, THEN

Stage Down Now = True

Compressor Sequencing

Compressor staging is based primarily on compressor run-hours and starts. Compressors that have less starts will normally start before those with more starts. Compressors that have more run-hours will normally shut off before those with less run-hours.

46 AGZ 010B through 034B IOMM AGZB1

In the event of a tie on number of starts, the lower numbered compressor will start first. In the event of a tie on run-hours, the lower numbered compressor will shut off first. Run hours are compared in terms of tens of hours.

Next On = 1 if compressor 1 starts <= compressor 2 starts or compressor 2 not available, and compressor 1 available

Next On = 2 if compressor 1 starts > compressor 2 starts or compressor 1 not available, and compressor 2 available

Next Off = 1 if compressor 1 run hours > compressor 2 run hours

Next Off = 2 if compressor 1 run hours <= compressor 2 run hours

Compressor State

A compressor will start when all of the following conditions exist:

• The compressor is “next on”

• Stage Up Now is set

• The compressor is available to start

A compressor will stop when any of the following conditions exist:

• Unit state = Off

• Low Ambient start attempt failed

• Stage Down Now is set, both compressors are running, and the compressor is “next off”

• Pumpdown is complete

Normal Shutdown

If a condition arises that requires the unit to shut down, but it is not an emergency situation, then a pumpdown will be performed. A normal shutdown will be initiated when any of the following occur:

• Unit State = Pumpdown

• Circuit Switch = Off

• Low Ambient Lockout

• A normal stage down occurs, and only one compressor is running

• Unit mode = Ice AND the ice setpoint is reached

Pumpdown Procedure

• If both compressors are running, shut off the appropriate compressor based on

sequencing logic

• With one compressor left running, turn off hot gas output and liquid line output

• Keep running until evaporator pressure reaches the pumpdown pressure, then stop

compressor

• If evaporator pressure does not reach pumpdown pressure within two minutes, stop

compressor and log pumpdown failure alarm

Rapid Shutdown

A situation may arise that requires the unit to shut down immediately, without doing a pumpdown. This rapid shutdown will be triggered by any of the following:

• Unit State = Off

• Stop Alarm

All compressor and liquid line outputs are turned off immediately for a rapid shutdown.

IOMM AGZB1 AGZ 010B through 034B 47

Liquid Line Solenoid

ALARM

Red Alarm Light

The liquid line output shall be on any time a compressor is running and the unit is not performing a pumpdown. This output should be off at all other times.

Using the Controller

4x20 Display & Keypad

The 4-line by 20-character/line liquid crystal display and 6-key keypad are shown below.

Figure 15, Display (in MENU Mode) and Keypad Layout

Key to Screen Pathway

Air Conditioning

MENU Key

VIEW

< <

SET

ARROW Keys (4)

ENTER Key

Note that each ARROW key has a pathway to a line in the display. Pressing an ARROW key will activate the associated line when in the MENU mode.

Getting Started

There are two basic procedures to learn in order to utilize the MicroTech II controller:

1. Navigating through the menu matrix to reach a desired menu screen and knowing where

a particular screen is located.

2. Knowing what is contained in a menu screen and how to read that information or how

to change a setpoint contained in the menu screen.

Navigating Through the Menus

The menus are arranged in a matrix of screens across a top horizontal row. Some of these top-level screens have sub-screens located under them. The general content of each screen and its location in the matrix are shown in Figure 17. A detailed description of each menu begins on page 51.

There are two ways to navigate through the menu matrix to reach a desired menu screen.

One is to scroll through the matrix from one screen to another using the four ARROW keys.

The other way is to use shortcuts to work through the matrix hierarchy. From any menu screen, pressing the MENU key will take you to the top level of the hierarchy. The display will show ALARM, VIEW, and SET as shown in Figure 15. This corresponds to the second row of screens on Figure 17. One of these groups of screens can then be selected by pressing the key connected to it via the pathway shown in Figure 15.

For example, selecting ALARM will go the next row of menus under ALARM (ALARM LOG or ACTIVE ALARM). Selecting VIEW will go the next level of screens under VIEW (VIEW UNIT STATUS or VIEW UNIT TEMP). Selecting SET will go to a series of screens for looking at and changing setpoints.

48 AGZ 010B through 034B IOMM AGZB1

MENU Key

The MENU key is used to switch between the shortcut method (known as the MENU mode and as shown in Figure 15) and scrolling method (known as the SCROLL mode). The MENU mode is the shortcut to specific groups of menus used for checking ALARMS, for VIEWING information, or to SET setpoint values. The SCROLL mode allows the user to move about the matrix (from one menu to another, one at a time) by using the four ARROW keys. A typical menu screen is shown in Figure 16.

Pressing the MENU key from any menu screen will automatically return you to the MENU mode as shown in Figure 15.

Figure 16, Display in the Shortcut (SCROLL) Mode and Keypad Layout

Air Conditioning

MENU Key

VIEW UNIT STATUS Unit = COOL Compr. #1/#2=OFF/OFF Evap Pump = RUN

ARROW Keys

ENTER Key

Menu Screens

Various menus are shown in the controller display. Each menu screen shows specific information; in some cases menus are used only to view the status of the unit, in some cases they are used for checking and clearing alarms, and in some case they are used to set setpoint values.

The ARROW keys on the controller are used to navigate through the menus. The keys are also used to change numerical setpoint values contained in certain menus.

Changing Setpoints

Pressing the ENTER key changes the function of the ARROW keys to the editing function as shown below:

LEFT key Default, changes a value to the factory-set default value. RIGHT key Cancel, cancels any change made to a value and returns to the original setting. UP key Increment, increases the value of the setting DOWN key Decrement, decreases the value of a setting.

These four edit functions are indicated by one-character abbreviation on the right side of the display (this mode is entered by pressing the ENTER key).

Most menus containing setpoint values have several different setpoints shown on one menu. When in a setpoint menu, the ENTER key is used to proceed from the top line to the second line and on downward. The cursor will blink at the entry point for making a change. The ARROW keys (now in the edit mode) are used to change the setpoint as described above.

IOMM AGZB1 AGZ 010B through 034B 49

When the change has been made, press the ENTER key to enter it. No setting is changed until the ENTER key is pressed.

For example, to change the chilled water setpoint:

1. Press MENU key to go to the MENU mode (see Figure 15).

2. Press SET (the UP Key) to go to the setpoint menus.

3. Press UNIT SPs (the Right key) to go to setpoints associated with unit operation.

4. Press the DOWN key to scroll down through the setpoint menus to the third menu which

contains Evap LWT=XX.X°F.

5. Press the ENTER key to move the cursor down from the top line to the second line in

order to make the change.

6. Use the ARROW keys (now in the edit mode as shown above) to change the setting.

7. When the desired value is achieved, press ENTER to enter it. The cursor will

automatically move down.

At this point, the following actions can be taken:

1. Change another setpoint in this menu by scrolling to it with the ENTER key

2. Using the ENTER key, scroll to the first line in the menu. From there the ARROW keys

can be used to scroll to different menus.

50 AGZ 010B through 034B IOMM AGZB1

SET UNIT SPs, (1)

SET UNIT SPs, (2)

SET UNIT SPs, (3)

SET UNIT SPs, (4)

SET UNIT SPs, (5)

SET UNIT SPs, (6)

(7)

SET UNIT SPs, (8)

SET UNIT SPs, (9)

Figure 17, Menu Matrix

UNIT COMP REFRIGERANT FANS

VIEW UNIT

STATUS 1-3

TEMP 1-3

(Right side of matrix continued from above)

"ALARM" MENUS "SET" MENUS

ALARM LOG (LAST)

TYPE, TIME

ALARM LOG

(NEXT TO LAST)

ALARM LOG

(SECOND TO LAST)

ALARM LOG

LAST 25 SHOWN ⇓

SET UNIT SPs,

VIEW COMP #1

STATUS

⇐ Continued ⇐

ACTIVE ALARM

(1)

TYPE, TIME

ACTIVE ALARM

(2)

TYPE, TIME

ADDITIONAL

ACTIVE ALARM

(3)

CLEAR/VIEW

"VIEW" MENUS

VIEW COMP #2

STATUS

MODE

COOL/GLYCOL/

ICE

TEMP EVAP LWT

MISC

CLOCK

ENGLISH

PROTOCOL

EVAP OFFSET

COND OFFSET

(10) LWT OFFSET

(11) AMBIENT

OFFSET

(12) ENTER

PASSWORD

VIEW EVAP/COND PRESS (1) VIEW UNIT

VIEW EVAP APPROACH (2)

SET COMP

SPs (1)

STOP/START

SET COMP

SPs (2) INTER-

STAGE

SET LIMIT

ALARMS (1)

EVAP PRESS

SET LIMIT

ALARMS (2)

FREEZE/ FLOW

ALARMS (3)

COND PRESS

ALARMS (4)

PHASE/VOLT

LOW AMB

LOCKOUT

ALARMS (5)

LOW EVAP PR

"MENU"

VIEW FAN

STAGING

SET FANS (1)

STAGES

FANTROL

SET FANS (2)

STAGE ON

SET FANS (3)

STAGE OFF

Menu Structure (Hierarchical)

As discussed previously, a hierarchical menu structure can be used to access the various screens. One to twelve levels are used with two or three being typical. Optionally, the last menu selection can access one of a set of screens that can be navigated with the UP/DOWN ARROW keys (see the scrolled menu structure below).

IOMM AGZB1 AGZ 010B through 034B 51

Menu selection is initiated by pressing the MENU key that changes the display from a

ALA RM LO G

regular data screen to a menu screen. Menu selections are then made using the arrow keys according to labels on the right side of the display (the arrows are ignored). When the last menu item is selected, the display changes to the selected data screen. An example follows showing the selection of the “VIEW COMPRESSOR (n) screen.

Suppose the initial screen is as below or any other menu screen:

(da ta ) (da ta ) (da ta )

After pressing the MENU key, the top level menu screen will show:

< ALARM < VIEW < SET

After pressing the “VIEW” menu key, a menu screen will show:

VIEW < UNIT < COMPRESSOR < REFRIGRANT < FANS

Selection of any of these will advance to the appropriate data menu. For example, after pressing the “REFRIGERANT” menu button, the selected data screen will show:

VIEW REFRIG PSI °°°°F

SAT EVAP XXX.X XX.X SAT COND XXX.X XX.X

The ARROW keys will automatically return to the “scroll” mode at this time.

Screen Definitions VIEW

This section contains information on each screen. The menu screens are in order of the matrix in Figure 17, going from left to right and then down when there are sub-menus. Many menus are self-explanatory.

VIEW UNIT

VIEW UNIT STATUS (1) Unit = AUTO Cool Stages=0 Evap Pump = RUN

52 AGZ 010B through 034B IOMM AGZB1

Unit states can be:

Ice Delay=xxhr XX mn

VIEW UNIT TEMP (1)

VIEW UNIT TEMP (2)

VIEW UNIT TEMP (3)

Auto Off:Ice Mode Timer Off:All Comps Disabled Off:Unit Alarm Off:Keypad Disable Off:Remote Switch Off:BAS Disable Off:Unit Switch Auto:High LWT Pulldn Auto:Cycle Timers Auto:Wait for load Auto:OAT Lockout Auto:Evap Recirc Auto:Wait for flow Auto:Pumpdown Auto:Evap Press Low Auto:Cond Press High Off:Test Mode

as determined from the Unit State variable, the Unit Mode setpoint, the Unit Enable and the presence of an alarm.

Pump states can be: Off Start Run

VIEW UNIT STATUS (2) Stg Up Delay=XXX sec Stg Dn Delay=XXX sec

Ice delay line is only visible when in the ICE mode.

VIEW UNIT STATUS (3) D.O. D.I. 12345678 123456 00000000 000000

Evap LWT = XX.X°°°°F Outside Amb = XX.X°°°°F LWT Target = XX.X°°°°F

LWT Pulldn=XX.X °°°°F/m Control Band=XX.X °°°°F

StgUp@ XX.X Dn@ XX.X Start Unit @ XX.X Shutdown Unit @ XX.X

See page 39 for an explanation of these settings.

VIEW COMPRESSORS

VIEW COMP#1 (1) State = OFF LEAD Cycle Timer: XXmin Manual Disable

Cycle timer only visible when active. Manual Disable visible only when compressor is disabled via manual enable setpoint.

IOMM AGZB1 AGZ 010B through 034B 53

VIEW COMP#1 (2) Hours = XXXXX Starts = XXXXX

Above two screens duplicated for compressor #2.

VIEW REFRIGERANT

VIEW REFRIG (1) EVAP Press = XX.Xpsi COND Press - XX.Xpsi

With R22 Refrigerant With R407C Refrigerant

VIEW REFRIG (2) VIEW REFRIG (2) SAT EVAP = XXX.X°°°°F Evap Dew = XXX.X°°°°F SAT COND = XXX.X°°°°F Cond Mid = XXX.X°°°°F EvapApproach = XX.X°°°°F EvapApproach = XX.X°°°°F

See page 40 for an explanation of saturated temperatures for R22 and R407C.

Approach is the difference between the leaving fluid temperature and the saturated evaporator temperature. It is an indication of the evaporator efficiency; an increasing approach temperature indicates decreasing heat transfer efficiency.

VIEW FANS

VIEW FANS Stages ON = X of X

Screen Definitions – ALARM

ALARM ACTIVE (X) ALARM ACTIVE (X) Alarm Description No more alarms hh:mm:ss dd/mmm/yyyy Press ENTER to clear all active alarms

If the unit is off on a shutdown alarm or running but in a limit alarm condition, the cause and date will appear in the upper screen. If there is a simultaneous occurrence of more than one alarm, the others will appear in additional screens below this one, accessed by the DOWN ARROW. Either type alarm will light a red light in back of the LEFT-KEY. The light will go out when the fault is cleared.

To clear the fault, scroll down to the last screen and press ENTER. If other faults have appeared, they will all be cleared at the same time.

54 AGZ 010B through 034B IOMM AGZB1

ALARM LOG (1)

h Condenser Press

Hig hh:mm:ss d/mmm/yyyy

The last 25 alarms, either shutdown or limit, are shown in this menu with subsequent menus stored under it. ARROW DOWN from this menu will go to the next-to-last alarm, ARROW DOWN again will go to the second from last, and so on through the last 25 occurrences. The screens are numbered (1), (2), (3), etc.

Screen Definitions – SET

Changing setpoints; in general, setpoints are changed as follows:

1. Select the desired menu by scrolling through SET menus with the UP and DOWN

ARROWS.

2. When the desired menu is selected, select the desired entry by moving between lines

using the ENTER key.

3. If a numerical value is being changed, use the INCREMENT key (UP ARROW) to

increase or the DECREMENT key (DOWN ARROW) to decrease the value of the setpoint.

If a word type setpoint (for example, YES or NO) is to be selected, the choices are loaded into the menu and selected by scrolling through the available setpoint options using the UP ARROW key.

4. Enter the desired value or word into the controller by pressing the SET key.

SET UNIT SETPOINTS (SP)

SET UNIT SPs (1) Unit Enable=OFF Mode=COOL Source=KEYPAD

Unit Enable is an external signal or a keypad setting that keeps the unit off when the setting is OFF and allows it to run if there is a call for cooling. The source for the signal is selected in the 4th line and can be:

1. KEYPAD, in which case the selection is made in line 2 and would be normally selected

as ON. This is the normal setting when no external signals are controlling the unit.

2. SWITCHES, in which an external switch is wired across terminals #25 and #35. (See

wiring diagram page 27).

3. NETWORK, used with BAS signal, which is wired to the three communication ports.

Unit Mode settings can be

1. COOL, normal setting used with chilled water air-condition applications.

2. COOL w/GLYCOL, used with low temperature, glycol applications. It allows a lower

LWT setpoint to be used.

3. ICE w/GLYCOL, used with ice storage systems, allows changing from chilled glycol

operation to lower temperature ICE operation. In ICE, the unit runs at full load until the ICE setpoint is reached, at which time the unit shuts off. A three-position switch wired to terminals #28 and #38 initiates the change from glycol cooling to making ice. (See wiring diagram on page 27.)

IOMM AGZB1 AGZ 010B through 034B 55

Set w/ FP Switch Off

T UNIT SPs (3)

SET UNIT SPs (2) Available Modes =COOL w/Glycol

Available Modes settings can be COOL, COOL w/Glycol, ICE w/Glycol, or TEST as selected from the available modes imbedded in the menu. The 4th line is a reminder that the ON/OFF switch on the front panel (FP) must be in the OFF position before the MODE can be changed. This prevents a mode change while the unit is operating.

SE Evap LWT = XX.X°°°°F Ice LWT = XX.X°°°°F EvapDeltaT= XX.X°°°°F

SET UNIT SPs (4) StartDelta= XX.X°°°°F StopDelta= XX.X°°°°F

Staging

StartDelta is the number of degrees above the temperature setting that determines when the lead compressor starts. Compressor start and stop is determined by the control band and

StartDelta settings. The control band is automatically set of 60% of the EvapDeltaT (chilled water temperature in minus chilled water temperature out) selected in menu 3 above. The staging routine has been changes in this software version compared to previous versions. See page 39 for more details and an example.

For a warm start-up the lead compressor will start at any temperature above the start temperature. The lag will start after the start interval has timed out. The chilled water temperature will begin to be pulled down. At shut down temperature, the lag compressor will shut off. If the temperature climbs above that temperature within the StageDownTimer setting (default at 30 sec.), the lead compressor will remain on. This would be normal operation. If for some reason the temperature does not rise, the lead compressor will also shut off.

SET UNIT SPs (5) Max Pulldn=X.X°°°°F/min

Evap Recirc= XXX sec LowAmbLock= XX.X °°°°F

SET UNIT SPs (6) Ice Time Delay=XXhrs Clear Ice Delay=No

56 AGZ 010B through 034B IOMM AGZB1

SET UNIT SPs (7) CLOCK dd/mmm/yyyy hh:mm:ss

SET UNIT SPs (8) Units = °°°°F/psi

Lang = ENGLISH Refrig = Select Type

Units settings are only °F/psi at the present time. °C/kPa will be available later.

Lang (Language) settings can be only ENGLISH at present.

Refrig (Refrigerant) selection is done at the factory prior to shippment.

SET UNIT SPs (9) Protocol = NONE Ident Number=001 Baud Rate=9600

SET UNIT SPs (10) Evaporator Refrig Press Sensor Offset= 00.0 psi

The pressure/temperature offsets on menus 10 through 13 correct the controller's display of the parameters. The sensors used in these units have a high degree of repeatability but may need correction (offset). An accurate pressure gauge or thermometer is used to determine the correct temperature or pressure. A positive or negative offset value is then entered to make the controller reading agree with the measured value.

SET UNIT SPs (11) Condenser Refrig Press Sensor Offset= 00.0 psi

SET UNIT SPs (12) Leaving Evaporator Water Temp Sensor Offset= 00.0oF

SET UNIT SPs (13) Outside Ambient Temperature Sensor Offset= 00.0oF

IOMM AGZB1 AGZ 010B through 034B 57

SET UNIT SPs (14) ENTER PASSWORD XXXX Active Password Level:None

Two four-digit passwords provide OPERATOR and MANAGER levels of access to changeable parameters. The passwords are preprogrammed into the controller. The Operator Password is 0100. Either password must be entered using the ENTER PASSWORD (12) screen before a protected setting can be changed.

This screen can be accessed either through the SET OTHER menu or by simply pressing the ENTER key while on one of the SET screens. The controller will automatically go from the screen with the setting change to this screen. After the correct password has been entered, the controller will automatically return to the original set screen.

Once a password has been entered, it remains valid for 15 minutes after the last key-press.

SET COMP SPs

SET COMP SPs (1) Clear Cycle Tmr=No Stop-Start =XXmin Start-Start =XXmin

This menu sets the anti-recycle timers. Stop-Start is the time required before starting a compressor after it has stopped. Start-Start is the time required before starting a compressor after the last time it has started. It recommended that these default values not be changed.

SET COMP SPs (2) InterStageUp=XXXsec InterStageDn=XXXsec

InterStageUp is the time delay since the last stage change before a compressor can stage on.

InterStageDn is the time delay since the last stage change before a compressor can stage off normally (not by an alarm).

SET COMP SPs (3) Compressor 1=Enable Compressor 2=Enable

ALARM SETPOINTS

SET ALARM LMTS (1) LowEvPr

Hold=XXXpsi

Unload=XXXpsi

58 AGZ 010B through 034B IOMM AGZB1

The LowEvPrHold and LowEvPrUnld have the same default value of 59 psi. If two compressors are running, the LowEvPrUnld is in effect and the lag compressor will be shut off to unload the unit. If one compressor is running, the LowEvPrHold is in effect and the lag compressor is prevented from starting, thereby holding the unit capacity.

The last action to take place is the shutoff of all compressors running when the LowEvPrStop setting is reached (default is 58 psi).

SET ALARM LMTS (2) Evap Freeze= XX.X°°°°F

EvapFlowProof=XXXsec

Evap Freeze (the unit freeze protection shutdown) is actually a stop alarm and shuts off the unit when the LWT reaches 36°F. It is cleared by going to the CLEAR ALARM menu in the ACTIVE ALARM hierarchy.

EvapFlowProof is the flow switch interlock. Closing the flow switch and therefor proving the existence of chilled water flow resets this trip.

SET ALARM LMTS (3) High Cond Pressure

Unload = XXXpsi

Stop = XXXpsi

HighCondPr (the unit high-discharge-pressure shutdown) is a stop alarm that shuts off the unit when the discharge pressure reaches the setting. The default setting is 380 psi. The Stop is a shutdown alarm that stops the unit when the discharge pressure reaches the setpoint.

SET ALARM LMTS (4) PhaseVoltage=YES/NO LowOATLockTmr=XXXsec

LowAmbientLock prevents unit operation below the setting. If the unit is equipped with the standard FanTrol pressure-activated control, the available range is 35°F to 60°F with a default of 35°F. With the optional SpeedTrol variable speed control, the range becomes –2°F to 60°F with default of 0°F. Input to line 3 of the next screen, SET FANS SP (1), informs the controller which type of control is installed and which range of setting to allow.

SET FANS STAGES

SET FANS SPs (1) Fan Stages= X Speedtrol = NO

The Fans line tells the controller the number of fans on the unit. The UP ARROW toggles between 1, 2, and 3. 1 is not used; 2 should be used for Models AGZ 010, 013, and 017; and 3 should be used for AGZ 020, 025, 029, and 034.

IOMM AGZB1 AGZ 010B through 034B 59

Speedtrol tells the controller whether the optional SpeedTrol is installed in the unit. The

#1 #2 #3

XXX XXX XXX

UNIT XXX XXX

vap Water Pump=OFF

UP ARROW toggles between YES and NO. The setting changes the range available: YES = 35°F to 60°F, with 35°F being the recommended setting; NO = -2°F to 60°F, with 0°F being the recommended setting.

SET FANS SPs (2) Stage ON psi

SET FANS SPs (3) Stage Off psi #1 #2 #

These two menus set the on and off staging pressures for the fans. The third fan stage setting is only for three fan units. These settings are used with both FanTrol and SpeedTrol. SpeedTrol takes effect when the last fan is running after FanTrol cycles off the others.

Screen Definitions – TEST

The test screens are only available when the unit is in TEST mode. Using these screens, any digital output can be controlled manually.

TEST UNIT (1) Alarm Signal= OFF E

TEST UNIT (2) Liquid Line Sol=OFF Compressor #1 = OFF Compressor #2 = OFF

TEST UNIT (3) Fan Motor #1 = OFF Fan Motor #2 = OFF Fan Motor #3 = OFF

60 AGZ 010B through 034B IOMM AGZB1

Editing, Review

Editing is accomplished by pressing the ENTER key until the desired field is selected. This field is indicated by a blinking cursor under it. The arrow keys shall then operate as defined below.

CANCEL ................... Reset the current field to the value it had when editing began.

DEFAULT................. Set value to original factory setting.

INCREMENT ............ Increase the value or select the next item in a list.

DECREMENT ........... Decrease the value or select the previous item in a list.

During edit mode, the display shall show a two-character-wide menu pane on the right as shown below.

SET UNIT SPs (X) <D (data) <C (data) <+ (data) <-

Additional fields can be edited by pressing the ENTER key until the desired field is selected. When the last field is selected, pressing the ENTER key switches the display out of “edit” mode and returns the ARROW keys to “scroll” mode.

BAS Interface

McQuay’s Protocol Selectability feature is available as a factory-installed option or as a retrofit item available for installation after the unit is shipped.

If an interface module was ordered, one of the following BAS interface installation manuals was shipped with the equipment. Additional copies of referenced McQuay documents may be obtained from the local McQuay sales office, from the local McQuay Factory Service office, from the McQuay Technical Response Center, located in Staunton, Virginia (540-248-0711) or downloaded from www,mcquay.com.

• IM 735, LONW

• IM 736, BACnet Communication Module Installation

• IM 743, Modbus Communication Module Installation

• ED 15062-0, Microtech II Chiller Protocol Information – BACnet and LONW

• ED 15063-0, Microtech II Chiller Unit Controller Protocol Information – Modbus

The above are trademarks or registered trademarks of their respective companies: BACnet from the American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc., LonTalk, LONMARK and LONWORKS from Echelon Corporation, and Modbus and ModbusRTU from Schneider Electric.

ORKS

 Communication Module Installation

ORKS



IOMM AGZB1 AGZ 010B through 034B 61

Service

Thermostatic Expansion Valve

WARNING

Disconnect and tag out all power sources to the unit before doing any service inside the unit. Failure to do so can cause severe personal injury or death.

CAUTION

Service on this equipment is to be performed by qualified service personnel with special regard to regulations concerning release of refrigerant to the atmosphere.

Note: Repeated tripping of equipment protection controls must be investigated and corrected.

The expansion valve is responsible for allowing the proper amount of refrigerant to enter the evaporator regardless of cooling load. It does this by maintaining a constant superheat. (Superheat is the difference between refrigerant temperature as it leaves the evaporator and the saturation temperature corresponding to the evaporator pressure.) Typically, superheat should run in the range of 8°F to 12°F (4.4°C to 6.6°C).

The superheat setting can be adjusted by removing the cap at the bottom of the valve to expose the adjustment screw. Turn the screw clockwise (when viewed from the adjustment screw end) to increase the superheat setting and counterclockwise to reduce superheat. Allow time for system rebalance after each superheat adjustment.

The expansion valve, like the solenoid valve, should not normally require replacement, but if it does the unit must be pumped down by following the steps involved when changing a filter-drier.

If the problem can be traced to the power element only, unscrew the element from the valve body without removing the valve, but only after pumping the unit down.

Filter-Driers

If the pressure drop across the filter-drier is in the 6 to 10 psi range, it should be monitored and changed when the pressure drop reaches 10 psi. To change the liquid line sealed filter, de-energize the unit and pump out the refrigerant. After changing the filter-drier, check for leaks before recharging and returning unit to operation.

Liquid Line Solenoid

The liquid line solenoid valve does not normally require any maintenance. It may, however, require replacement of the solenoid coil. The solenoid coil may be removed from the valve body without opening the system by disconnecting power to the unit. The coil can then be removed from the valve body by simply removing the nut or snap ring located at the top of the coil.

62 AGZ 010B through 034B IOMM AGZB1

Optional Controls

SpeedTrol Head Pressure Control

The SpeedTrol method of head pressure control operates in conjunction with FanTrol by modulating the motor speed on system #1 fan in response to condenser pressure. By reducing the speed of the last fan as the condensing pressure falls, the unit can operate to 0°F (-18°C) ambient air temperature.

The SpeedTrol fan motor is a single-phase, 230/460 volt, thermally protected motor specially designed for variable speed operation. The solid-state speed control is mounted in the unit control panel and is connected to a Schrader fitting on the liquid line. The control is factory-set to start modulating fan speed at 230 psig, and it will maintain a minimum condensing pressure of 170 to 180 psig. Minimum starting voltage for SpeedTrol motors is 120 volts.

A low ambient timer function is included in the microprocessor. When the solenoid valve and lead compressor are energized by the controller, the low pressure cutout control is bypassed and the compressor is allowed to start with the low pressure control open.

After about 2-3/4 minutes, the time delay will open and the low pressure cutout function is again operable. If the system has not built up enough evaporator pressure to close the low pressure setting, the compressor will stop.

Due to the vertical condenser design, it is recommended that the unit be oriented so that prevailing winds blow parallel to the unit length, thus minimizing effects on minimum ambient operation. If it is not practical to orient the unit in this manner, a wind deflector should be constructed.

Hot Gas Bypass

Hot gas bypass is a system for maintaining evaporator pressure at or above a minimum value. The purpose for doing this is to keep the velocity of the refrigerant as it passes through the evaporator high enough for proper oil return to the compressor when cooling load conditions are light. It also maintains continuous operation of the chiller at light load conditions.

The solenoid valve should be wired to open whenever the liquid line solenoid valve is energized. This can be accomplished by wiring the hot gas solenoid (SV5) in parallel with the liquid line solenoid at terminals 14 and 16. The pressure-regulating valve is factory-set to begin opening at 58 PSIG (32°F for R-22) when the air-charged bulb is in an 80°F ambient temperature. The bulb can be mounted anywhere as long as it senses a fairly constant temperature at various load conditions. The compressor suction line is one such mounting location. It is generally in the 50°F to 60°F range.

Figure 19 indicates that when the bulb is sensing 50°F to 60°F temperatures, the valve will begin opening at 54 PSIG. This setting can be changed as indicated above, by changing the pressure setting, remove the cap on the bulb and turn the adjustment screw clockwise. To lower the setting, turn the screw counterclockwise. Do not force the adjustment beyond the range it is designed for, as this will damage the adjustment assembly.

The regulating valve opening point can be determined by slowly reducing the system load (or increasing the required chiller water temperature setting indicated on the unit thermostat), while observing the suction pressure. When the bypass valve starts to open, the refrigerant line on the evaporator side of the valve will begin to feel warm to the touch.

IOMM AGZB1 AGZ 010B through 034B 63

Bypass Valve

Suction Line

Remote Bulb

External Equalizer

Connection to Suction

After Expansion Valve

8090100

110

(

)

WARNING

The hot gas line may become hot enough to cause injury in a very short time. Avoid contact during valve checkout.

On installations where the condensing unit is remote from the evaporator, it is recommended that the hot gas bypass valve be mounted near the condensing unit to minimize the amount of refrigerant that will condense in the hot gas line during periods when hot gas bypass is not required.

Figure 18, Hot Gas Bypass Piping

Hot Gas Bypass

Solenoid Valve

Adjustable

Side of Evaporator

Discharge

Hot Gas

Line

Figure 19, Hot Gas Bypass Adjustment

VALVE OPENIN

30 40 50 60 70

REMOTE BULB ADJUSTMENT RANGE

TEMP (°F) AT BULB LOCATION

To Evaporator Inlet

RANGE

ADJUSTMENT

MODEL AGZ 029 – 034, Post 2004 Production

Model AGZ 029 and 034 built after January 2004 may have a hot gas bypass valve as shown as shown in Figure 20.

64 AGZ 010B through 034B IOMM AGZB1

The valve is adjusted using the adjusting screw show in the drawing. The range is 0 to 100 psi with about 16 psi change for one turn of the screw. Turning clockwise will increase the valve setting.

The load must be varied to properly set these valves. The load should be decreased so that the suction pressure decreases. The valve is then adjusted to maintain the correct suction pressure, which is the normal pressure at full load. The load should then be increases above the valve setting so that it closes. Operation can be checked by again reducing the load and noting when the valve opens (a hissing sound and/or pressure rise at the valve outlet indicates that the valve has opened).

Figure 20, ACZ 033 - 039 Hot Gas Bypass Valve

Adjusting Screw

IOMM AGZB1 AGZ 010B through 034B 65

Troubleshooting Chart

Troubleshooting can present risks of severe personal injury or death from burns, cuts, electrocution, strangulation and asphyxiation. Troubleshooting must be done by trained, experienced technicians only.

Table 22, Troubleshooting Chart

PROBLEM POSSIBLE CAUSES POSSIBLE CORRECTIVE STEPS

1. Main switch open

2. Fuse blown, breakers open

COMPRESSOR WILL NOT RUN

COMPRESSOR NOISY OR VIBRATING

HIGH DISCHARGE PRESSURE

LOW DISCHARGE PRESSURE HIGH SUCTION PRESSURE

LOW SUCTION PRESSURE

UNIT WILL NOT LOAD OR UNLOAD LOAD/UNLOAD INTERVAL TOO SHORT

COMPRESSOR LOSES OIL

MOTOR OVERLOAD RELAYS OPEN OR BLOWN FUSES COMPRESSOR THERMAL SWITCH OPEN

3. Thermal overloads tripped

4. Defective contactor or coil

5. System off by protection device

6. No cooling required

7. Liquid line solenoid will not open

8. Motor electrical problem

9. Loose wiring

1. Refrigerant flooding compressor

2. Improper line support

3. Worn compressor

1. Noncondensables in system

2. Refrigerant overcharge

3. Fan not running

4. Dirty condenser coils

5. FanTrol out of adjustment

1. Faulty condenser control

2. Low refrigerant charge

3. Low suction pressure

1. Excessive load

2. Expansion valve overfeeding

1. Lack of refrigerant

2. Evaporator dirty

3. Clogged filter-drier

4. Expansion valve malfunctioning

5. Low condensing temperature 1 Faulty controller sensor/broken wire

2. Stages not set for application

1. Erratic water thermostat

2. Insufficient water flow

1. Lack of refrigerant

2. Suction superheat too high

3. Crankcase heater burned out

1. Low voltage during high loads

2. Defective or grounded motor wiring

3. Loose power wiring

4. High condensing temperature

5. Unbalanced voltage

1. Operating beyond design conditions 1. Add facilities so conditions are within allowable

WARNING

1. Close switch

2. Check electrical circuits and motor windings for shorts. Check for overloads and loose connections. Replace fuse or reset breaker.

3. Check unit when back on line, auto reset

4. Repair or replace

5. Determine cause and correct

6. None, should start on call for cooling

7. Repair or replace coil

8. Check motor for open or short circuit, or burnout

9. Check all wire junctions. Tighten all terminals.

1. Check expansion valve setting

2. Relocate or add supports

3. Replace

1. Remove with authorized procedures

2. Remove excess

3. Check electrical circuit

4. Clean coil

5. Adjust FanTrol setting

1. Check condenser control operation

2. Check for leaks. Add refrigerant

3. See low suction pressure steps below

1. Reduce load or add capacity

2. Check remote bulb. Regulate superheat

1. Check for leaks. Repair and replace refrigerant.

2. Clean chemically

3. Replace

4. Check and adjust for proper superheat

5. Check discharge pressure control settings

1. Replace

2. Adjust thermostat setting

1. Replace

2. Adjust flow

1. Check for leaks and repair

2. Adjust superheat

3. Replace crankcase heater

1. Check supply voltage

2. Replace compressor

3. Check all connections and tighten

4. See steps for high discharge pressure

5. Check voltage. Contact power company.

limits

66 AGZ 010B through 034B IOMM AGZB1

All McQuay equipment is sold pursuant to McQuay’s Standard Terms and Conditions of Sale and Limited Product Warranty.

This document contains the most current product information as of this printing. For the most up-to-date product information, please go to www.mcquay.com

800 432 1342• www.mcquay.com IOMM AGZB1 (10/07)

McQuay AGZ 034BS, AGZ 034BM, AGZ 010BM Operation Manual

Specifications and Main Features

Frequently Asked Questions

User Manual